Floating Material

+ Hentai about a secret sexual relationship between students and teachers (two students in Floating Material, and one in Furueru) + No rape and just girls trying to get their teacher to feel the same way about them that they do about him - Floating Material's animation is better being done by Poro and Furueru's animation only stands out at a few moments but is otherwise below average  

- Both are hentai & ecchi genres -Two heroines vs one MC -Light romance & school life  

+ One teacher and two girls + Individual sex scenes up until the last scene which involves all three characters + One bustier girl and one more average girl (kind of similar hair colors as well if that really matters) - Cosplay Rakuen's girls are a teacher and a student while floating Material's girls are both students 

Hentai that involve an older guy and a younger girl but don't have a very large age gap (I assume). Both times the girls start off shy but gradually open up to the guy romantically. 

These two hentai both have three-way relationships between an older guy and two school girls. Both are made by Poro so they have very similar animation. Oni Chichi involves father/daughter relationships, while Floating Material has teacher/student relationships. Oni Chichi has less consensual sex than Floating Material. 

Both are hentai about one main couple and in both there is a third girl who is hardly ever involved and mostly watches the development. The animation is kind of similar and both female leads have similar body sizes. 

-Similar art -Both have the same atmosphere -The same producers