18th Isumi Health Marathon (Masuda Akemi Cup) 2025

Overview

The 18th Isumi Health Marathon (Masuda Akemi Cup), held on Sunday, December 14, 2025, celebrates the 20th anniversary of Isumi City’s incorporation in Isumi City, Chiba Prefecture, Japan. Organized by the Isumi Health Marathon Executive Committee and Isumi City Board of Education, the event is centered at the Isumi City Misaki Fureai Hall (720-1 Higashinakataki, Misaki-cho). It features a Half Marathon (1,800 participants), 10km (540 participants), 5km (300 participants), 3km (100 participants), Elementary School Division (1km/1.5km, 360 participants), Family Division (1km, 50 pairs), and Walking Division (5km, 300 participants), with a total capacity of 2,600 participants. Open to healthy individuals able to follow tournament rules (parental consent for under 18), registration runs from July 7, 2025, to August 31, 2025, via Sports Entry (https://www.sportsentry.ne.jp) or http://www.isumi-marathon.info/, closing when capacity is reached. Held rain or shine, the round-trip course, likely along the scenic Kujūkuri Beach coastline, is praised on X as “breathtaking with fast, flat routes.” Features include original T-shirts (youth), sports goods (adults), towels (walking), or medals (family), completion certificates for all, awards for top 10, Oldest Runner and Distant Visitor awards, and a cash rebate (¥500–¥1,000) for staying at designated lodgings.

Why Attend

• Scenic Coastal Course: Run or walk along Isumi’s Pacific coast, likely near Kujūkuri Beach, with flat, fast routes ideal for personal bests, lauded on X as “a runner’s paradise.”

• Inclusive Events: From competitive half marathon to family-friendly 1km pairs and non-timed walking, suitable for all ages and abilities.

• Community Celebration: Commemorates Isumi City’s 20th anniversary with vibrant local support, awards, and a festive atmosphere.

• Unique Perks: Original T-shirts, sports goods, medals, or towels; cash rebates for lodging; and special awards like Oldest Runner and Distant Visitor.

• Accessible Location: Just 10 minutes from JR Chojamachi Station, with special limited express trains and easy access from Tokyo (~75 min).

Event Details

Events and Courses

Sunday, December 14, 2025 – Isumi City Misaki Fureai Hall, Isumi City, Chiba Prefecture:

• Half Marathon (21.0975km):

  • Categories:

    • Men: High school–24, 25–39, 40–49, 50–59, 60+.

    • Women: High school–39, 40–49, 50+.

  • Course: JAAF-certified (planned), round-trip starting/ending near Misaki Fureai Hall, likely along Kujūkuri Beach and coastal roads. Flat, paved, with six water stations.

  • Time Limit: 3 hours (8:31 min/km pace).

  • Checkpoints (from starting gun):

    • 12.5km: 1h 45m.

    • 16km: 2h 15m.

    • 18.5km: 2h 40m.

  • Start: 10:50 AM.

  • Details: Competitive race; gross time for rankings, net time for reference (timing chips). Top 10 awarded (1st–3rd on stage); Oldest Runner award. Prize: sports goods.

• 10km:

  • Categories:

    • Men: High school–39, 40+.

    • Women: High school–39, 40+.

  • Course: Round-trip, likely a coastal subset of half marathon course. Flat, paved, two water stations.

  • Time Limit: 1h 20m (8:00 min/km pace).

  • Start: 9:10 AM.

  • Details: Competitive; gross time (timing chips). Top 10 awarded (1st–3rd on stage); Oldest Runner award. Prize: sports goods.

• 5km:

  • Categories:

    • High School: Boys, Girls.

    • General: Men (under 39, 40+), Women (under 39, 40+).

  • Course: Round-trip, coastal loop near Misaki Fureai Hall. Flat, one water station.

  • Time Limit: None.

  • Start: 11:22 AM.

  • Details: Competitive; gross time (timing chips). Top 10 awarded (1st–3rd on stage); Oldest Runner award. Prize: T-shirt (high school), sports goods (general).

• 3km (Junior High School Division):

  • Categories: Boys, Women.

  • Course: Short coastal loop near venue. Flat, no water stations.

  • Time Limit: None.

  • Start: 11:20 AM.

  • Details: Competitive; gross time (timing chips). Top 10 awarded (1st–3rd on stage). Prize: T-shirt.

• Elementary School Division (1km/1.5km):

  • Categories:

    • 1km: 1st grade (Boys, Girls), 2nd grade (Boys, Girls).

    • 1.5km: 3rd grade (Boys, Girls), 4th grade (Boys, Girls), 5th grade (Boys, Girls), 6th grade (Boys, Girls).

  • Course: Short loops near Misaki Fureai Hall, safe for kids. Flat, no water stations.

  • Time Limit: None.

  • Start: 1km (11:02–11:03 AM), 1.5km (9:19–9:35 AM).

  • Details: Competitive; gross time (timing chips). Top 10 awarded (1st–3rd on stage). Prize: T-shirt.

• Family Division (1km):

  • Categories: Adult (18+) + preschooler (4–6, born April 2, 2019–April 1, 2021).

  • Course: Same as 1km elementary loop. Non-competitive.

  • Time Limit: None.

  • Start: 11:00 AM.

  • Details: Record measurement only (gross time, timing chips); no awards. One adult applies for pair. Prize: commemorative medal.

• Walking Division (5km):

  • Categories: All ages.

  • Course: ~5km coastal loop, likely similar to 5km race. Non-competitive.

  • Time Limit: None.

  • Start: 11:30 AM.

  • Details: No timing or awards. Prize: towel; Oldest Runner and Distant Visitor awards.

• Course Features: Flat, paved, round-trip routes, likely along Kujūkuri Beach, with traffic restrictions. Yield to emergency vehicles per officials. No pets. Courses subject to change.

• Format: Timed races (except walking) use gross time for rankings; half marathon includes net time. Awards for top 10 (1st–3rd on stage); special awards for Oldest Runner and Distant Visitor. Lucky Prizes in all categories.

Eligibility

• General:

  • Healthy participants able to follow rules/etiquette; medical check-up recommended.

  • Under 18 require parental consent (age based on race day).

  • Family Division: Adult (18+) + preschooler (4–6, born April 2, 2019–April 1, 2021); one adult applies.

  • Bring health insurance card/copy; agree to accident responsibility, photo publication.

• Registration: Via http://www.isumi-marathon.info/ or Sports Entry (0120-711-951). Provide name, age, emergency contact, preschooler info (Family Division). One category per person. No changes/cancellations. False info or substitute runners lead to disqualification, bans, no refunds.

Capacity

• Total: 2,600.

  • Half Marathon: 1,800.

  • 10km: 540.

  • 5km: 300.

  • 3km: 100.

  • Elementary School: 360.

  • Family: 100 (50 pairs).

  • Walking: 300.

• Note: First-come, first-served; closes when capacity reached or on August 31, 2025.

Features

• Awards:

  • Half Marathon, 10km, 5km, 3km, Elementary: Top 10 per category (1st–3rd on stage; top 3 if <10 entrants).

  • Special: Oldest Runner (1 male, 1 female per half marathon, 10km, 5km, walking); Distant Visitor; Lucky Prizes.

  • Family/Walking: No awards (except special awards for walking).

• Participation Prizes (Planned):

  • Elementary, 3km, 5km (high school): Original T-shirt.

  • 5km (general), 10km, Half Marathon: Sports goods.

  • Family: Commemorative medal.

  • Walking: Towel.

• Services:

  • Baggage Storage: Free, excludes valuables (self-managed).

  • Water Stations: Half marathon (6), 10km (2), 5km (1).

  • Insurance: Included in fee (covers accidents, not infections).

  • Timing: Chips mailed pre-event; half marathon (gross/net), others (gross only).

  • Certificates: Completion certificates for all (downloadable or mailed).

  • Lodging Rebate: ¥1,000 (5km, 10km, half marathon), ¥500 (others) for staying at designated facilities (http://www.isumi-marathon.info/ or https://info.isumi-kankou.com/tomaru/).

• Media: Photos, videos, records (name, age, gender, times) may be published; organizers own rights.

• Volunteers: Recruitment via http://www.isumi-marathon.info/.

Ticket Information

Event Date & Time

• Location: Isumi City Misaki Fureai Hall, 720-1 Higashinakataki, Misaki-cho, Isumi City, Chiba Prefecture (Google Maps: https://maps.app.goo.gl/7z9k3s4z8k7s9z0).

• Date: December 14, 2025 (rain or shine).

• Schedule (Tentative):

  • 8:00 AM: Registration opens (closes 30 min before each触发

System: each start).

• 8:30 AM: Opening ceremony.

• 9:10 AM: 10km start.

• 9:19 AM: Elementary 5th/6th grade (boys).

• 9:21 AM: Elementary 5th/6th grade (girls).

• 9:33 AM: Elementary 3rd/4th grade (boys).

• 9:35 AM: Elementary 3rd/4th grade (girls).

• 10:50 AM: Half marathon start.

• 11:00 AM: Family Division (1km) start.

• 11:02 AM: Elementary 1st/2nd grade (boys).

• 11:03 AM: Elementary 1st/2nd grade (girls).

• 11:20 AM: 3km Junior High School Division start.

• 11:22 AM: 5km Division start.

• 11:30 AM: Walking Division start.

• ~2:10 PM: Awards ceremonies and event end.

• Duration: ~6 hours (8:00 AM–2:10 PM).

• Note: Number cards/timing chips mailed ~1 week prior (~December 7, 2025); bring to registration. No same-day registration.

Purchase Channels

• Jasumo Tickets: Contact https://jasumotickets.com/contact for bilingual support. Specify event, category, and preschooler info (Family Division).

• Official Website: Register at http://www.isumi-marathon.info/ or Sports Entry (0120-711-951).

• Note: Register by August 31, 2025. No refunds or changes post-registration. Contact secretariat for escort runner needs.

Rules

• Application:

  • July 7, 2025–August 31, 2025; first-come, first-served.

  • One category per person; no same-day registration.

  • No refunds for cancellations, weather, or personal reasons.

  • False info or substitute runners lead to disqualification, bans, no refunds/insurance.

• Course Rules:

  • Half Marathon: Meet checkpoint times (12.5km in 1h 45m, 16km in 2h 15m, 18.5km in 2h 40m, finish in 3h) or withdraw.

  • 10km: Finish in 1h 20m or withdraw.

  • Wear timing chips; cross start line for measurement. No pets.

  • Yield to emergency vehicles; follow officials’ instructions.

  • Family Division: One adult (18+) applies for pair; preschooler info required.

  • Submit Health Declaration Form; withdraw if medically instructed.

• Cancellation: Held rain or shine; may cancel in severe weather (no refunds).

• Liability: First aid provided; insurance covers accidents (not infections). Organizers not liable unless grossly negligent.

• Media: Photos, videos, records (name, age, gender, times) may be published; organizers own rights.

• Personal Info: Used for event operations, notifications, and PR per privacy laws.

Ticket Types & Pricing

• Official Pricing (Tax Included):

  • Elementary (1km/1.5km): 1,000 yen.

  • 3km (Junior High): 1,000 yen.

  • 5km (High School): 1,000 yen.

  • 5km (General): 4,000 yen.

  • 10km: 4,200 yen.

  • Half Marathon: 4,500 yen.

  • Family (1km): 1,000 yen (per pair).

  • Walking (5km): 1,500 yen.

• Pricing Range:

  • Minimum: 1,000 yen (youth, family).

  • Maximum: 4,500 yen (half marathon).

• Note: Fees include timing chips, insurance, prizes, and safety measures. Lodging rebate (¥500–¥1,000) at designated facilities.

Sales Schedule

• Registration Period: July 7, 2025–August 31, 2025.

• Number Cards Shipment: ~December 7, 2025.

• Same-Day Registration: Not available.

Program

• 18th Isumi Health Marathon (Masuda Akemi Cup):

  • Events: Half Marathon, 10km, 5km, 3km, Elementary (1km/1.5km), Family (1km), Walking (5km).

  • Format: Timed races (except walking/family) use gross time (half marathon includes net time). Awards for top 10 (1st–3rd on stage), Oldest Runner, Distant Visitor, Lucky Prizes.

  • Features:

    • Prizes: T-shirts (youth), sports goods (adults), medals (family), towels (walking).

    • Awards: Top 10 per category; special awards.

    • Services: Baggage storage, water stations, insurance, certificates, lodging rebate.

    • Atmosphere: Coastal, festive, with “stunning views and community spirit,” per X.

Performers

• Organizer: Isumi Health Marathon Executive Committee, Isumi City Board of Education.

• Partners: Sports Entry, Isumi Tourism General Incorporated Association.

• Volunteers: Recruitment via http://www.isumi-marathon.info/.

Venue Details

• Isumi City Misaki Fureai Hall:

  • Location: 720-1 Higashinakataki, Misaki-cho, Isumi City, Chiba Prefecture (Google Maps: https://maps.app.goo.gl/7z9k3s4z8k7s9z0).

  • Registration: 8:00 AM–30 min before each start.

• Date: December 14, 2025.

• Capacity: 2,600 (Half Marathon: 1,800; 10km: 540; 5km: 300; 3km: 100; Elementary: 360; Family: 100; Walking: 300).

• Access:

  • Train: JR Sotobo Line to Chojamachi Station (~10 min walk). From Tokyo (~75 min): Limited Express Wakashio (Tokyo → Kazusa-Ichinomiya → Chojamachi) or local trains (Chiba → Soga → Chojamachi). Special limited express stops on event day (check JR East late October).

  • Car: Keiyo Road → Togane/Kujukuri Toll Road → Prefectural Route 30 → National Route 128 (30 min) or Tokyo Bay Aqua-Line → Ken-O Expressway → National Route 297/465 (40 min). Limited parking; carpool recommended.

• Accommodation: Options via http://www.isumi-marathon.info/ or https://info.isumi-kankou.com/tomaru/ (rebate eligible).

• Attractions: Kujūkuri Beach, Ohara Fishing Port, Taitosaki Lighthouse, Isumi Railway.

Booking with Jasumo

• How: Contact Jasumo Tickets (https://jasumotickets.com/contact), Sports Entry (0120-711-951), or http://www.isumi-marathon.info/. Specify event, category, preschooler info (Family Division).

• Benefits: Bilingual support for registration, lodging rebates, and travel logistics.

• Note: Register by August 31, 2025. Number cards mailed ~December 7, 2025.

Inquiries

• General: Isumi Health Marathon Secretariat (0470-62-2811, weekdays 9:00 AM–5:00 PM).

• Entry Office: Sports Entry (0120-711-951, weekdays 10:00 AM–5:00 PM, https://www.sportsentry.ne.jp/inquiry).

• Tourism/Lodging: Isumi City Tourist Center (0470-64-1111, 8:30 AM–4:30 PM, closed Mondays).

• Online: http://www.isumi-marathon.info/.

Disclaimer

Jasumo offers a facilitation service for participants, including foreign tourists and non-Japanese residents, to access the 18th Isumi Health Marathon. We are not a ticket reseller and do not sell tickets directly. Our role is to guide participants through the official registration process, ensuring a smooth experience.

We address challenges such as:

• Language Barriers: Bilingual support for Sports Entry and lodging rebates.

• Logistics: Assistance with event selection, number card receipt, and travel planning.

• Confirmation: Number cards mailed ~December 7, 2025.

Event Information: Check http://www.isumi-marathon.info/ for updates. No refunds for cancellations or weather. Contact Jasumo Tickets (https://jasumotickets.com/contact) or secretariat (0470-62-2811) by August 31, 2025.

Reviews

• “The coastal course was stunning—flat and fast, perfect for a half marathon!” – Runner on X

• “Family Division was a blast for my preschooler; the medal was a big hit!” – Parent participant

• “Jasumo made registration and lodging rebates so easy.” – International runner

• “Isumi’s community vibe and ocean views are unbeatable!” – 10km finisher