Prunus lannesiana 'Kanzan', Cerasus Sato-zakura Group 'Sekiyama' Koidz,[1] Kwanzan or Sekiyama, Japanese 関山) is a flowering cherry cultivar.

It was developed in the Edo period in Japan as a result of multiple interspecific hybrids based on the Oshima cherry.

In winter they produce red buds, opening to 5-centimetre (2 in) diameter deep-pink double flowers.

[4][5] The trees, which are usually propagated by chip budding or grafting, prefer a well-drained location in full sun.

Compared with Yoshino cherry, a representative Japanese cultivar, it is popular because it grows well even in cold regions, is small and easy to plant in the garden, and has large flowers and deep pink petals.