I bought this cute bean leaf 6 years ago and it didn't grow much since then, at some point I almost lost it due to root rot and it lost some leaves , so now it seems even smaller than when I got it...
I tried to look up this cultivar name and it turns out that its ancestor is one of a few selected siblings of cross between Neofinetia falcata 'Benikujaku' and Neofinetia falcata 'Yodonomatsu'.

According to info on pungnan website :https://pungnan.or.kr/bbs/board.php?bo_table=class&wr_id=222 there are few different types of Benimusou. But I still didn't quite understand differences between types, maybe because of the google translation gaps. Mine seems to fit the look of the one on the second picture where leaves don't fully open:













