Former Hotta Kojoen Tea House

A Tea Room Built on a Rhombus

The Former Hotta Kojoen Tea House (旧堀田古城園茶室, Kyū-Hotta Kojōen Chashitsu) is a single-storey timber tea room laid out on a rhombus-shaped plan, built in 1933 in Ote, Kofu City, Yamanashi Prefecture, and registered as a Registered Tangible Cultural Property on February 4, 2021.

It stands on its own in the southeast corner of the former restaurant grounds, at the end of a row that begins with the north and south annexes. With a building area of 12 square metres it is the smallest of the six registered structures here, capped by a hipped sheet-metal roof over exposed-frame Shinkabe walls.

The national database notes a 2017 renovation. Kofu City describes the building as a rhombus-shaped structure renovated as a tea room, and no source consulted for this article confirms that it served as a Chashitsu from the start.

Why It Was Registered

Five of the six Hotta Kojoen buildings were registered for their contribution to the historic landscape. The Former Hotta Kojoen Tea House is the exception: it was registered under a different criterion, as a building that serves as a model of form. What earned the listing is the shape itself.

From outside it looks much like the two annexes. Inside, though, the four-and-a-half-mat room is set on a rhombus, a format the Agency for Cultural Affairs calls distinctive. Fitting rectangular Tatami into a room with no right angles is the puzzle at the heart of the building.

The alcove is unconventional too. In place of a standard Tokonoma, a low cupboard and a biwa-dana, a raised shelf named after the lute once displayed on it, sit side by side. The agency calls the result a small gem brimming with sukiya taste.

What to Look For

When Kofu City received the property, this building had become an awkward mix of a rectangle and a rhombus. The restoring architects examined traces in the foundations, found that the building had been a rhombus from the outset, and rebuilt the missing parts to restore the original footprint.

The tea house originally sat on top of an existing retaining wall, so it was dismantled, moved and reassembled. Old photographs and physical evidence also showed that the first roof was metal, and that finish was reinstated.

Inside, the irregular four-and-a-half-mat room is paired with a Mizuya preparation area. There is no crawl-through nijiriguchi entrance. Instead, shoji panels set into genji-style sliding doors slide open for ventilation, serving the guest entrance and the host's service door. The lattice window is fitted with a glazed sash salvaged from an old house elsewhere in Kofu, reused as a hanging screen.

Visitors often link the rhombus to the Takeda-bishi, the diamond crest of the Takeda clan, but no record of the designer's intent has been found. Look at the building from the southeast and you will notice that its outside corners are not square.

Visiting the Tea House

The exterior of the Former Hotta Kojoen Tea House can be viewed from the garden during museum hours. To go inside, request an entry permit at the information desk; interior visits are limited to 1 hour.

The room is small and holds only a few people at a time. If you want to study how the tatami are cut to fit, pick a quiet moment.

Directions, opening days and fees for the whole site are on the Former Hotta Kojoen page.