Kairakuen is one of three parks along with Kenroku-EN in Kanazawa and Koraku-EN in Okayama, recognized as the most beautiful in Japan.

Kairakuen in MiTo city, the center of Ibaraki Prefecture, was defeated at the instruction of the Tokugawa Nariaki, who led the fief of MiTo, in 1841, and the General public was admitted a year later. Nariaki loved plum trees, so on-site kairakuen was laid a large plum grove, and throughout the ownership of MiTo they were planted very much. Japanese plum admired ruler its combination of spiritual and practical: plum blossomed first, decorating the arrival of spring, and autumn gave a delicious fruit that can be canned and eaten in the winter.

Nariaki was very active and progressive ruler, and after his death received the name "the Burning Prince". Park kairakuen was conceived by him as one of the attempts to reduce the distance between the authorities and ordinary people. In the documents preceding the establishment of the Park, was designated the goal of this project as effort and rest." Besides the Park, Nariaki created a school to train young samurai Kodokan next. After efforts in it, the disciples were to enjoy a relaxing holiday in the Park.

Park Kairakuen planted about 100 different varieties of plums, three thousand trees that begin to bloom in late February or early March. From February 20th to the last day of March in the Park is held plum blossom Festival, which attracts lots of Japanese people and visitors. Only during the festival at the local train station stops the train on the other days Express passes without stopping. In April in the Park kairakuen bloom of Sakura, and then begins the time of flowering azaleas.

The Park boasts a Shinto Shrine erected in honor of the representatives of the Tokugawa clan, as well as wooden pavilion Kobota in three floors. This building held many cultural events with the participation of poets and artists, as well as citizens of advanced age (over 80 years) and Nariaki.

During the Second world war the Park kairakuen was almost completely destroyed by bombs, but in 1958 it was restored.