Buttobi!! CPU

Both are about h4x0rz and have some ecchi content. 

Both involve a male lead and a female android living together. 

Similar style of hentai from the same era. Lovable characters. Over all feel-good story. 

I found these anime surprisingly similar. Both are about a girl (Robot in CPU/Mutant in Sekirei) protecting their master from the others that are the same kind as them. Sekirei is the better anime by a long shot, but odds are if you enjoyed this as I did, then you will for sure in enjoy Sekirei. P.S. both anime feature -Beautiful women are "servants" to their master's wishes -Battles of epic proportion -Very plain male leads -Yes, nudity is in both as well. 

If you like 80's style art, wierd sexual practices, silly slapstick comedy, hilarious plot twists, and unorthydox stories then check out Buttobi CPU. 

Buttobi CPU is pretty much an older Chobits. You'll enjoy it xD They are close to being the same other than the hentai in Buttobi.  

They're both robots that are ordered in by a horny Japanese master, and service him everyday.