Didn't use a walkthrough (is there one ?) but this game is grindy as hell (and I usually don't mind it that much, I love Witch Trainer) but what you have to do and when is sometimes too vague, and you don't know as clearly as in other games if the choices you made had some impact and moved the grinding one step forward. Also, the lack of H-scenes makes it almost impossible to stumble upon a H-scene you haven't seen already, which would make the grinding easier to accept. Still like the art style, unusual but working well (it's usually only one of these in other games).
Also I was using cheating engine (just added +1 to relationship with each character), and about Hitomi's quest it told me I had seen all content with her for the update. Later I forgot about that and still went on the beach to try to convince her to get naked, and she did ! So the cheat engine was wrong. New problem ensues : I went on to the beach after she hinted she will come back. I tried all the things I can on this beach the week after and never seen her again here. So now the cheat engine is correct ? You just see her naked and in v0.682 maybe there's more ? Not that I particularly care about this character, but so much clics and repeated dialogue choices just for that is bordering on masochism. The more the quest is long/boring/hard the biggest the reward should be. Getting jerked off in the theater is a bigger reward, and to get it you just have to ask and pay a few dollars. See the problem ?