Overview
Kozushima (神津島) is a small volcanic island in the Izu archipelago, located roughly 180 km south of Tokyo in the Philippine Sea. It belongs to Tokyo Metropolis administratively — a fact that surprises many visitors — and is reached by ferry or small aircraft from the mainland. The island covers approximately 18 square kilometres and is home to a permanent population of around 2,000 people.
The island is most celebrated for the exceptional clarity of its coastal waters, particularly around Maehama Beach and the diving sites off its rugged coastline. The interior rises steeply to Mount Tenjo (天上山), a protected natural monument whose summit plateau offers sweeping views of neighbouring islands on clear days. Much of the island falls within the Fuji-Hakone-Izu National Park, which shapes what development is permitted here.
Kozushima has a distinctly unhurried character. Facilities are modest, English signage is limited, and the island actively discourages mass tourism in favour of environmental preservation. Visitors who come prepared — with basic Japanese phrases, cash, and realistic expectations — tend to find it one of the more rewarding escapes within reach of Tokyo.
Before You Go
Visas
Japan has its own entry requirements that vary by nationality. For current visa rules, check the TravelerPulse Visas section and the official website of the Japanese Ministry of Foreign Affairs or your nearest Japanese embassy.
What to Bring
- Cash. ATM access on the island is limited; bring sufficient yen from the mainland. Japan Post Bank ATMs on the island accept some international cards, but verify this before you travel.
- Snorkelling or diving gear. Some equipment can be rented locally, but availability is not guaranteed — confirm with dive operators in advance.
- Sun protection and layers. Summer sun on the water is intense; evenings can be cool, especially in spring and autumn.
- Japanese phrasebook or translation app. English is spoken very little outside of any tourist-oriented businesses.
- Motion sickness remedies if you plan to take the overnight ferry, as seas between the Izu islands can be rough.
Connectivity
Mobile coverage exists on the island via major Japanese carriers, but can be patchy in the hills. Download offline maps before departure.
Getting There
Ferry from Tokyo (Takeshiba Pier)
Tokai Kisen operates ferry services from Takeshiba Pier in central Tokyo to Kozushima. Journey times vary depending on the vessel and route — the overnight large ferry takes roughly 8–10 hours, while faster jet-foil services can reduce this considerably but are weather-dependent and do not run year-round. Check the Tokai Kisen website for current schedules, fares, and seasonal availability before booking.
By Air
New Central Airservice (新中央航空) operates small propeller aircraft connecting Chofu Airport (near Tokyo) with Kozushima Airport. Flight time is approximately 45–55 minutes. Seats are limited and services are suspended in poor weather. Book well in advance, especially in summer. Verify current schedules directly with the airline.
Practical Note
Both ferry and air services are subject to cancellation due to strong winds or rough seas — a real consideration in this part of the Pacific. Build flexibility into your itinerary, particularly at the end of your stay, so a weather delay does not cause you to miss onward commitments.
Getting Around
Kozushima is small enough that many areas are reachable on foot or by bicycle, though the hilly terrain makes cycling demanding in places. Rental bicycles and scooters are available from operators near the ferry terminal — verify availability and rates locally, as options can be limited during peak summer weekends.
A limited community bus service connects the port area with some parts of the island, but schedules are infrequent. Taxis exist but are scarce; it is advisable to arrange transport in advance if needed. Most visitors find a combination of bicycle and walking sufficient for a several-day stay.
For the Mount Tenjo hike, the main trailhead is accessible on foot from the village. The upper plateau is a protected zone with rules about staying on marked paths — observe posted guidance carefully.
Where to Stay
Accommodation on Kozushima is primarily small family-run minshuku (Japanese bed-and-breakfast style guesthouses) and a limited number of small hotels or lodges. Many minshuku include dinner and breakfast in the room rate (a common arrangement in rural Japan called 'two meals included'), which is convenient given the limited restaurant options in the evening.
Booking well in advance is essential for summer visits (particularly July–August and public holiday weekends), when the island becomes popular with Tokyo day-trippers and short-stay visitors. Accommodation fills quickly during these periods.
To find currently operating properties, search Japanese travel booking platforms (such as Jalan or Rakuten Travel) as well as international platforms, and filter for Kozushima (神津島). Verify amenities — air conditioning, private bathrooms, and Wi-Fi are not universal in minshuku.
There is a campsite on the island; verify its current status, facilities, and reservation requirements with the Kozushima Village office or tourism association before assuming it is available.
Things to See & Do
Swimming and Snorkelling
Maehama Beach is widely regarded as one of the clearest-water beaches in the Izu islands, and its popularity reflects this. Arrive early in summer to secure space. Several smaller coves around the island offer quieter alternatives; local guesthouses can point you toward less-visited spots.
Diving
Kozushima has a small number of diving operators offering guided dives for certified divers and introductory experiences for beginners. Visibility in the water is frequently exceptional. Verify which operators are currently active and confirm certification requirements directly with them.
Mount Tenjo (天上山)
The hike to the summit plateau is the island's principal land-based activity. The terrain is volcanic and the upper area is a designated natural monument — camping and collecting plants or rocks is prohibited. On clear days, views extend to Niijima, Shikinejima, and sometimes Miyakejima. Allow several hours for a round trip and bring water.
Stargazing
Light pollution on Kozushima is minimal, and the night sky on clear evenings is notably dark. The island has been recognised for its stargazing conditions. No dedicated observatory facility is guaranteed to be open — check locally.
Relaxed Island Life
Much of what makes Kozushima worthwhile is simply being on a quiet Japanese island — watching fishing boats, eating fresh seafood, and moving slowly. Do not over-schedule.
Food & Drink
Dining options are modest in number. The village near the port has several small restaurants and izakaya (Japanese pub-style eateries) serving local seafood including sashimi, grilled fish, and island-caught shellfish. Dishes using locally caught fish are the safest culinary bet and are generally fresh and well-prepared.
There are a small number of grocery stores where you can pick up basics, snacks, and drinks. Stock up for day hikes or beach days, as there are no food stalls in remote areas of the island.
Alcohol is available at restaurants and shops. The izakaya culture is relaxed and welcoming, even if communication requires some patience without shared language. Pointing at dishes ordered by other diners or at picture menus works reasonably well.
Vegetarians and those with dietary restrictions should note that many Japanese dishes include fish-based stocks even when they appear vegetable-forward. Communicating dietary needs in written Japanese before ordering is advisable.
Practical Information
Money
Carry sufficient cash in yen. While some businesses may accept card payment, many smaller establishments and minshuku operate cash-only. The island has limited ATM infrastructure — Japan Post Bank ATMs are the most likely to accept international cards, but confirm this before relying on them.
Medical
Kozushima has a small medical facility, but serious medical emergencies would require evacuation to the mainland — weather permitting. Bring a personal supply of any prescription medications and a basic first-aid kit.
Emergency Numbers
- Police: 110
- Fire and Ambulance: 119 These are standard Japan-wide numbers.
Environmental Rules
Much of the island is within a national park. Removing natural materials, disturbing wildlife, and going off marked trails in protected zones is prohibited. Follow posted signs carefully — enforcement does occur and the island community takes conservation seriously.
Language
Basic Japanese phrases (greetings, numbers, food terms) will make your visit significantly smoother. Translation apps with a downloaded Japanese language pack are a practical fallback.
Safety
Kozushima is a safe destination by most measures. Petty crime is rare in this tight-knit community. The main practical risks are environmental: strong currents in certain coastal areas (heed local warnings before entering the water), rough seas that can strand visitors beyond their planned departure date, and the island's volcanic geology, which means the terrain can be unstable in places.
Check weather and sea conditions before planning water activities. Local dive operators and guesthouse owners are typically the best sources of current conditions advice. Japan's Meteorological Agency website provides forecasts in Japanese; translation apps can help interpret these.
Typhoons can affect the Izu islands between late summer and early autumn. Monitor forecasts if travelling in this window and have contingency plans for extended stays.
