Tabelog ratingOimoyasan Koshin is a takeout stand dedicated to one of Japan’s classic snacks: the sweet potato. Located in the bustling basement food hall of the Daimaru department store, directly connected to Tokyo Station, it specializes in `daigaku imo` (candied sweet potato) and `suitei poteto` (creamy sweet potato cakes).
The main attraction is the `daigaku imo`, sold in large, glossy chunks. Customers appreciate that the sweet syrup and black sesame seeds are often packed separately, allowing you to control the sweetness. The shop frequently offers a `tabekurabe` (tasting comparison) set, letting you try different potato cultivars like the fluffy 'Ai-komachi' or the dense 'Miyabi'. The other highlight is the `suitei poteto`, a baked sweet potato cake praised for its exceptionally smooth, melt-in-your-mouth texture. With a refrigerated shelf life of about three days, these sweets are a popular choice for a Tokyo souvenir.
However, the experience can be inconsistent. Several reviewers report brusque or inattentive staff and slow service at the register. The quality of the potatoes can also vary, with some batches described as dry or soggy. Prices are higher here than at other branches, reflecting its prime location in Tokyo Station.
Reviewers in 2024–2026 paid around ¥1,950 for a `tabekurabe` tasting set and about ¥950–¥1,000 for a standard 250g portion of `daigaku imo`. Individual sweet potato cakes cost about ¥380–¥400. While not a bargain, it offers reasonable value for a specialty snack if you're already passing through the station.
- Location: In the B1F food hall of the Daimaru Tokyo department store, accessible directly from Tokyo Station.
- Booking: Walk-ins are standard. Reservations are not necessary for individual purchases.
- Payment: Credit cards, electronic money, and QR code payments are accepted.
- Practicalities: This is a takeout-only counter. Note that there is often a minimum purchase weight of 250g for the candied potatoes. Utensils are not always provided, so ask if you need them. The counter is in a narrow, often crowded aisle.
- Parking: Paid parking is available as part of the department store.
- Smoking: The entire area is non-smoking.
