Boin

Besides the fact that in Boin the protagonist is a teacher and in Jutaijima a normal student and Jutaijima has much more darker stuff comparatively to the more mundane setting of Boin, both hentai have a similar variety of girls to chose from, which comes with various female students and a big chested sensei with glasses, this last one is really similar in both (Jutaijima has a blonde doctor too), there's also only one guy at play with these of ladies, so there's the harem aspect in both. 

In Oni Chichi there's the incest aspect, but it's in a way about a teacher fiddling with his students, in fact two of those students and the ones who get almost all the scenes are reminiscent of the ones found in Boin, at least in terms of character design (one is blonde, the other with short red/pink hair and both with big breasts). If you like the idea of a sensei with the protagonist role in a hentai, go for any of these. 

There's the same of plot of a lucky teacher being intimate with his students or just one student in the case of Bakunyuu Oyako, which also features the busty mother of the girl, in Boin there's also a sensei at play, she's not a milf, at least I don't think so, but she's definitely in the more mature part as the busty mom, and finally both are hentai from the same time, mid 2000's where animation for hentai didn't have as much budget as older OVAs, nor had the technology to conceal the lack of frames, so there's the same energy from both.