Since I always was too lazy for months I've searched the internet for a clanname and came up with these:

白川  - Shirokawa (white river)

永 滝  or 長 滝  -Nagataki (eternal or long waterfall)

子 池 - Koike (small pond)

子岡 -Kooka (small hill)

I don't know, I like them all. Best looking in my eyes is Nagataki, best sounding is Shirokawa , cute sounding Koike and idk I also like Kooka. I took them because of the meanings since I want something with water. Kooka I choosed because I  always imagined her clan living between little hills, forests and a river/ waterfall.