Mmm . . . "Ren" is written with the character for "love", and "ko" is written with the character for "heart".

[ patting the pink fish ]

"O" is written with the character for "great", and "nou" is written with the character for "strong". "Nou" can be read as "koi", which is "carp" - so it's a play on words.

[ patting the black fish ]

I wondered if we were doing too poorly recently, but this game has me somewhat relieved . . .