Innoshima and Murakami Naval Forces: Learning History of Maritime Warriors on a Shimanami Kaido Island

Innoshima, belonging to Onomichi City in Hiroshima, is an island located almost midway along the Shimanami Kaido linking Onomichi and Ehime. Long flourishing as a strategic point of the Seto Inland Sea, in medieval times it became the base of the Innoshima Murakami clan, one of the families of the Murakami Naval Forces that dominated the Inland Sea. Popular as a waypoint on the cyclists' mecca of the Shimanami Kaido, it is an appealing island offering history, spectacular scenery, and gourmet.

Highlights

The Murakami Naval Forces were a naval (pirate) group that ruled the medieval Seto Inland Sea, divided into three families of the Mishima Murakami: Noshima, Kurushima, and Innoshima. They set up sea checkpoints to collect tolls and served as maritime pilots, in effect a clan that governed sea traffic. Innoshima has the "Innoshima Suigunjo," a castle-style naval museum rare in Japan, where you can learn the history of these maritime warriors through armor, weapons, and old documents. The Murakami clan's graves also remain at Konrenji Temple at its foot.

Innoshima is also known as the birthplace of the citrus fruit "hassaku." Discovered at a temple on the island in the late Edo period, this citrus is still widely cultivated in Hiroshima and Ehime as a specialty. The "hassaku daifuku" savored at island shops, with its exquisite balance of mild tartness and sweet bean paste, is a specialty well worth trying. Near the summit of Mt. Hakutaki in the island's north, a group of five hundred rakan stone Buddhas made in the late Edo period stands in rows, with the multi-island beauty of the Seto Inland Sea spreading beyond. The spectacular scene woven by the expressive stone Buddhas and the islands is Innoshima's finest photo spot.

Seasonal Enjoyment

Winter, when citrus ripens, and the comfortable spring and autumn are recommended. Winter is the season for hassaku and other citrus, when direct-sale shops and storefronts turn colorful. Summer showcases views of the blue sea and bridges, and the multi-island beauty from Mt. Hakutaki is clearly visible. On clear autumn days, the vantage lets you see distant island silhouettes, ideal for the view.

Access and Practical Information

You can enter the island by car from the Innoshima-kita IC and Innoshima-minami IC on the Shimanami Kaido. From Onomichi, access by bicycle or ferry is also possible, and many stop by as a waypoint on a Shimanami Kaido ride. Because highlights such as Innoshima Suigunjo and Mt. Hakutaki are scattered across the island, a car or rental bicycle helps you get around efficiently. Confirm each facility's hours and admission via official information.

Practical Travel Notes

For a stop midway through a ride, resting with citrus sweets such as hassaku daifuku is recommended. You can approach Mt. Hakutaki near the summit by car, but the path around the five hundred rakan is undulating, so comfortable shoes are reassuring. Allow about half a day for the naval castle, Mt. Hakutaki, and gourmet combined. Touring together with other Shimanami Kaido islands such as Ikuchijima and Mukaishima lets you enjoy each island's character. Budgets center on transport, admission, and dining costs.

A Word of Advice

Learning the pirates' history at Innoshima Suigunjo before climbing Mt. Hakutaki makes the story of the Murakami Naval Forces, set against the Seto Inland Sea, feel far more vivid. Do not forget to savor the citrus sweets unique to the birthplace of hassaku, and enjoy history, scenery, and taste all together.

📚 Sources

The information in this article is organized from tourism details on Innoshima published by the city of Onomichi and the Onomichi tourism association, along with public guidance on historic sites and facilities related to the Murakami pirates (Murakami navy). Opening hours and fees for each facility can be checked through the operators' official information. Fees, hours, and access may change, so please always confirm with official sources before you set out.

Visitor Checklist

• Estimated time: About half a day to tour the main spots, or a full day to take in the island slowly.
• What to bring: Prepare cash for admission and food, and comfortable shoes since there is plenty of outdoor walking.
• Getting around: As the island is linked by the Shimanami Kaido, travel by car or rental bicycle is convenient.
• Suggested route: Center your plan on the historic sites and museum tied to the Murakami pirates, then extend to the island's scenic and specialty spots.
• What to wear: The coast can be windy on some days, so prepare clothing suited to the season.

Practical Information for Your Visit

The following details are for Innoshima Suigun Castle (3228-2 Innoshima Nakanosho-cho, Onomichi City), the main sight on Innoshima.

• Opening hours: 9:30-17:00 (last entry 16:30; on January 2 and 3, 10:00-15:00)
• Closed: Every Thursday (except public holidays), and December 29 to January 1
• Admission (Honmaru Museum): 330 yen for adults / 160 yen for children (elementary and junior high school students). Groups of 30 or more pay 220 yen for adults and 110 yen for children. Visitors with a disability certificate and one accompanying carer are admitted free of charge
• Admission during special and touring exhibitions: 500 yen for adults (400 yen for groups) / 160 yen for children (110 yen for groups). The period runs from May 1, 2026 to November 25, 2026
• Parking: Free of charge (50 spaces)
• Telephone: 0845-24-0936 (managed by the Innoshima Tourism Association, a general incorporated association)
• Access: About 2 km from the Innoshima-kita Interchange on the Shimanami Kaido, or about 4 km from the Innoshima-minami Interchange. By public transport, take the bus bound for Innoshima Habu Port from JR Onomichi Station for about 37 minutes to the Kanamebashi stop, change to the local bus bound for Ohama for about 8 minutes, get off at Suigunjo-iriguchi, then walk about 10 minutes

Mount Shirataki and its Gohyaku Rakan stone statues (Innoshima Shigei-cho, Onomichi City) are also worth visiting. Admission is free of charge, and parking is available at the Shirataki Flower Line parking area / eighth-station parking area (218 m from the summit, about a 10-minute walk) and at the Omotesando parking area (618 m from the summit, about a 30-minute walk).

(Sources: Onomichi City official website, Innoshima Suigun Castle; Innoshima Kanko Navi (Innoshima Tourism Association) official website)