In Finnish and Estonian, this is a form of Richard. It was among the top 100 most popular boys’ names in Finland in 2004, ranking in at #48. The designated name-day is February 7th in both countries.
It is also a Japanese male name (very rarely female), and can have various meanings depending on the Kanji but the most popular is 陸 (Riku), “land, shore, continent.”
Riku is a familiar character name in anime, manga, and games — for example, in Kingdom Hearts, where Riku is a central figure.
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