Ryusui Seiryoin (??? ??, Seiryoin Ryusui, born August 9, 1974) is a Japanese novelist, active in mystery and various other fields.
He was born in 1974, in Hyogo Prefecture, Japan.
He won the 2nd Mephisto Prize in 1996 while in Kyoto University, and started to work as a novelist.
After that, Ryusui published over 60 novels.
His works are always controversial.
The JDC (Japan Detectives Club) series has inspired tribute novels by authors like Otaro Maijo and Nisio Isin.
In 2007, he achieved the publication of the series, "What a perfect world!", for 12 consecutive months.
In the same year, he carried out "Doumo tour", the autograph sessions for 12 consecutive months held in Japanese major cities, and made a great success.
On May 1, 2009, he launched "bbbcircle", his official website, with Kai Chamberlain, a Canadian cartoonist.