Houkago Nyannyan

Both are about a boy and girl discussing and exploring things. Both have simple but cute animation. Difference is that in Peeping Life they are exploring the ways to save the energy and in Houkago Nyannyan they are exploring sex. 

Two different sex stories, the first being about two curious virgins having sex in a classroom (though Junk Land has a restroom scene before that). Fairly unique character animation is in both. 

These anime are similar in how they are both straightforward vanilla hentai, have several different short stories and similar "bed sex" scenes. They are different though because their art styles are very different. There are also more character archetypes in Idol Kouhosei, and Idol Kouhosei is a POV. 

Similar animation style. The episodes are composed of unrelated chapters.