Oneechan ga Kita

Both are about brocons that thinks as their brothers are cute and have slight comedy. 

both are about a step-sister and brother relationship (the sister who has an abnormal obsession about her brother), but Onee-chan ga Kita it's only about 3 minutes. 

A short comedy series focusing on the relationships between the brothers and sisters. Though Super Seisyun Brothers has four main cast who are blood related siblings and has some funny interacting dialogue. Onee-chan ga Kita focuses on non-blood related siblings where the sister loves her brother really much. 

Both are comedies with short episodes, the main heroines acts the same. 

Both have a step-sister, but in Onee-chan ga Kita, the step-sister is clingy to the main protagonist, unlike in ImoCho, where she is kind of shy toward her step-brother. 

Both feature an expressive middle school protagonist getting lots of affection from an older girl. They each have a very wholesome vibe, and have plenty of comedy. They also both have cute art styles. 

Both are short anime series with a cute female mc, who is overly fond of something (tasting food in Wakako-zake, brother in Oneechan ga Kita). 

Both are animated shorts, but while one male MC lives with 4 blood-related sisters, the latter lives with his step sister. 

Both anime have similar artstyle and comedy skits. If in Acchi Kocchi the girl is shy and tsundere so she can't express her feeling properly to the boy she likes, in Onee-chan ga Kita the girl is too clingy and stalker-y in showing her love for her step-brother that her brother thinks of her as a weird sister. Despite that, the girls have similar expressions. 

Similarity : + Both anime about love between siblings Different : + Tomoya only have one sister, Youtarou have 13 step-sisters + Onee-chan ga kita is less fanservice compared to Baby Princess 

-Both are short -Both involve a guy and a girl to which they are close (take that as you will) -if you were to take their relationship as a manzai routine, one of them is the tsukkomi(stright man), and the other is the boke (idiot) -both are very cute and enjoyable to watch, especially as an in between from serious anime -both have an OVA -both definitely should get more episodes 

Though Aki-Sora is more borderline porn, it has a similarity to Onee-chan ga kita, thanks to the older sister/younger brother aspect, and the fact, that the younger (not to mention feminine) male has to deal with the affection of his older sister. 

Fluffy random slice of life comedy. Kana and Ichika also have similar chara design. But the most important point is triangle/water-drop-shaped mouths. So if you like waterdrop-shape mouth you should try these anime. 

Brother-sister relationship. in Onee-chan, she is a step sibling who likes her brother. Whole in Ane Log, the brother likes his sister. But she won't accept it. One is a short series while the other an OVA. 

The shows heavily rely on humor, which mostly come from the girly protagonists reactions to the affections of the airhead heroine. 

- Really similar - Both are 3 minutes per episode - Sister suddenly starts living with her brother 

Similarity : + Both series is incest anime + The MC doesn't have relation blood with his/her siblings. They can become siblings because their parent is remarried Different : + Tomoya only have one sister, Ema have 13 brothers