HANA・BIYORI-kan, glasshouse of the HANA・BIYORI flower park (Yomiuriland)

HANA・BIYORI grew out of a project by the Yomiuriland company, operator of the neighbouring amusement park, which made it one of its seventieth-anniversary schemes and the first step of its "super amusement park" concept. The ground had been Seichi Kōen, a sanctuary park where Buddhist treasures were assembled in the 1960s: relics and a hair of the Buddha presented in 1964 by the governments of Ceylon and East Pakistan, the Pakistani-marble pagoda that holds them, a seventeenth-century tahōtō tower re-erected on the site in 1964, and bodhisattva statues designated Important Cultural Properties in 1950. These were kept in the part of the park now called the Sacred Forest.

Announced for 14 March 2020, the park opened on 23 March after a postponement caused by the pandemic, presenting itself as Japan's first entertainment-style botanical garden: a greenhouse where flowers, digital projections, otters, an aquarium and a café share the same roof. The Starbucks under the glass was the chain's first inside a botanical-garden greenhouse in Japan. Some of the furniture in the dining areas was made from estate trees felled by the typhoon of September 2019.

In 2021 the Dutch garden designer Piet Oudolf created his first garden in Japan here; it was planted by gardeners gathered from across the country, as he was unable to travel. On 6 March 2024 a hot-spring bathhouse, Kakei no Yu, opened on the former lookout hill, and its ticket also admits visitors to the flower park. The site was still operating in 2026, with night openings during the illumination season.

The greenhouse stands at the centre of the 40,000 m² park; Time Out Tokyo and the iko-yo website put its floor area at about 1,500 m². Official documents describe it as a glass greenhouse flooded with daylight that can be plunged into darkness: several times a day the glazing is blacked out and a projection show, presented as the first permanent installation of its kind in a Japanese botanical garden, turns flowers and walls into a digital set, with an ending that changes according to an analysis of the audience's emotions.

The interior is composed as a 360-degree floral set: more than 300 hanging baskets form a "flower chandelier" beneath the roof, a planted wall more than 20 m long and 2 m high is recomposed with the seasons, and the floor itself is planted. A large tree some four centuries old, the "parabolacho" (Spanish for "drunken tree", according to the park), serves as the symbol tree. The building also houses a Starbucks whose sign is made of living plants, an 8 m saltwater aquarium paired with a 3 m planted tank, an otter enclosure with a slide and an underwater cave, and a shop. Indoor terrace seats on the west side look out over the dry garden and the cultural properties of the Sacred Forest. Irrigation, streams and waterfalls across the park are fed by well water from the Tama hills.

The baskets of the flower chandelier combine begonias, fuchsias, petunias, geraniums and saxorum, replaced so that the building looks in full bloom all year; the wall compositions and floor beds follow the seasons, and the roughly 400-year-old parabolacho presides over the whole. The aquarium shows some forty species of fish from the seas of Okinawa, including clownfish and damselfish, against a backdrop of corals; the park gives the total as about a thousand fish. The otter enclosure also houses rabbits and guinea pigs.

Outside, Piet Oudolf Garden Tokyo blends perennials and grasses in a meadow-like planting designed to stay handsome down to the dry silhouettes of winter. The flower-lined paths around the greenhouse include a four-seasons garden, a sequoia lawn under the tallest tree on the estate, a rock garden of lilies and a hellebore garden; plum, cherry and spiraea bloom in spring, and fireflies can be seen in June along a stream. In the Sacred Forest, 2,000 red spider lilies flower around the pagoda from late September to early October, and the maples turn red over the pond in autumn.

HANA・BIYORI lies in the Tama hills, about ten minutes on foot from Keiō-Yomiuriland station on the Keiō Sagamihara line, which is also served by a free shuttle bus; the entrance is separate from that of the Yomiuriland amusement park, to which a connecting gate links the flower park from late morning. The greenhouse, the Sacred Forest and the Oudolf garden take two to three hours; the projection show runs several times a day, and re-entry is not allowed without an annual pass. Cherry blossom in spring, fireflies in June, spider lilies in late September, autumn maples and the "HANA akari" night illuminations are the high points. The neighbouring Kakei no Yu baths give access to the park, and Jindai Botanical Gardens lie a few kilometres to the north-east.