Nee, Chanto Shiyou Yo!

Similarity : + Love story between siblings + Sosuke & Kuya Sisters actually is step-sister + Both MC is still green about sex & woman, following main story will tell how both of them learn about that Different : + Sosuke only have 2, Kuya have 6 sisters 

Both hentai about older & younger sister having sex with their little brother 

First Love is a 3 episode OVA with 3 different stories & 3 different couples. If you like love between siblings, I recommend you to just watch the first episode of First Love which focuses on the love story between Kasumi & her brother.  

Similarity : Having sex with older sisters Different : Yuuta only have 2 sisters, both is biological sisters Kuuya have 6 sister from different mother 

Renketsu Houshiki is 3 episode OVA with 3 Different story & 3 Different genre If you only like incest route, then you just only need to watch episode 1 

I'll have this updated when I finish re-watching Nee, so I'll be general for now. The cast of Nee, Chanto Shiyou Yo! seems to be the inspiration behind the characters of Akame Ga Kill!, not only females characters but also our main male MC. From looks to personality, the cast of Nee... has been transferred to Akame in weird ways (like they put the characters from Nee in a blender and you get a mix of personas with an appearance of a blue haired demon ;)) I didn't even notice until I saw the blonde in Nee and looked at the Akame anime page, some of the characters have been straight pasted into Akame with fighting powers. Our precious Kaname is the inspiration behind icon character Akame's looks although personality was not wholly. read more 

They are the same in a way that the lucky male protagonist is living with a harem of girls at home who are all very ''attracted'' to him. Both anime has high quality art and animation and bot of them are visual novel adaptations. 

The same "homecoming to step-sisters whom live away" plot. 

Both have guy sleeping with his sisters  

Both male protagonists share many similarities. They are surrounded by great looking, attractive females in a house where they don't have much say (one is a butler while the other is the youngest, not to mention adopted, of 6 siblings). Both anime originated from H-games (visual novel). Both have extremely similar storyline. Why do I keep saying both? Both female leads (I am referring to Kaname and Shinra) are GORGEOUS and look VERY VERY similar!