Hi ! Can you be a little more specific please ?
I'm sorry, my memory is really blurry, as I remember this from long ago.So, I could only make out these details.
Ah, right, I remember it was a black and white manga. Whoops.
I'm not sure, but the boy with the grandpa has a strict family, and I think they are wealthy. So, the grandpa might not approve the boys' relationship, if they were together.
Hence, the robot? (￣∇￣") I might be mixing things up with Asobi Asobase, though. But I really believe the grandpa introduced a robot or android to his grandson, so he could experience how to date. Hahaha.
It's a Shounen-Ai manga where both of the boys are childhood friends, I think? Their story has something to do with bridges, where the friends often hang out.
One of the boys' grandpa has a human robot (if I remember correctly) which was supposed to be given to his grandson, in which his grandson can date?... I'm not sure if it's for that purpose, lolol. My mind is mixed up.
It kinda reminds me of that English-speaking Olivia robot in Asobi Asobase. At least, the setting is similar, I believe. Just without the comedy.