NHK ni Youkoso!, Me~teru no Kimochi Recommendations
Are you a shut-in, scared to go out and living in isolation? If so, excellent - these two are perfect for you!
Me-Teru No Kimochi is the spiritual brother of NHK. In both the main character are recluses (although Me-Teru's lead has been one for far longer) and in both a beautiful woman enters the picture, intent on changing their lives.
NHK is more believable and has a girl with small breasts, Me-Teru has a sillier premise and a woman with big breasts. If in doubt, go with the one with the bigger boobs - that's my suggestion.
In both, we follow the life of a male hikikomori and the female character who tries to change his life.