Does anyone know the names to these two Yaoi Mangas?

First Manga:
Okay from what I remember there was this little kid who fell for this somewhat older guy, who was, in fact, a scientist. The little kid was from a rich family and he offered the older guy some money in order to help him on a machine that he was working on.
The machine I believe could make small things into big things since the little kid had started liking the scientist guy, he decided to try out the machine and it worked!
He became big and older, which made it more easy to be with the scientist guy.
In the end of the manga, the scientist guy makes the little kid turn to his original size and age, but he would wait for him when he turns 18.

Second Manga:
I don't really remember much from this one aside from the seme going to stay with his dad and he goes into the back yard and a black hole opens, and it takes him back in time. Now that he's back in time he meets the younger self of his father and they fall in love.
But he eventually goes back to his real time and the rest is a bit confusing to explain,

Hopefully, someone has read these mangas and can be able to tell me their names. In advance thank you very much!