I read it years ago (2013 ish, and it was quite a few years old at that point- I wanna say 2008 ish?) and can't remember the name. I'll try and describe it as best I can;

a teen boy (art was a bit shota esque) lives with his uncle who is a scientist(?) and creates a twin "brother" (term was used very lightly) for him who is an android bc he's a bit of a shut in antisocial and he thinks it'll be good for him. shennanagans proceed; it was a fairly short manga.

both main characters had blue-grey eyes and hair. the android wore a black choker I believe. at one point he goes out and buys food for mc and mc also sends him to school in his place since they're identical. pretty sure one of their names started with "ch" something.

hope that's not too vague, but if anyone knows what the hell I'm talking about and can give me a title that'd be great!

FOUND IT - I remembered the mangaka and found it in her works. I was thinking of S-ka Chuuihou! and also realized I'd been missing some of her other works. Leaving this here in case anyone else is looking for it!!