The Problem is the partial Translation, wich simply locks you out from the Stray Quests. The Stray Quest are mostly the H Quests, but also some normal Quests. At a Point in the Game you must do Stray Quests for progressing the Main Story - so you are complete locked .
But even if the Stray Quests are unlocked without a Translation of the SP and AP Skills it is problematic to do the H Quests. because you need - especially for later Quests - some Reqiurements to activate them - like a specific Level of Lewdness or a learned AP Skill and if you spend too much AP points your Lewdness Level increases. The Problem here is than, that when you need for H Quest for exampel Lewdness 2 and you have Lewdness 3, the Quest dissapears.
So without a readable Translation impossible to play.