The male lead is a f*ckboy who would even sleep with his highschool neighbor on their first meeting after 4 years. And I bet the female lead would still end up fall in love with him.
I rarely go into a second male lead syndrom, but Shuuichi is a much better option. 😪
By the way, I don't mean to disrespect elders, but the grandma was really cruel. If she didn't want to take care of it, at least let someone else adopt it. And at least give it proper food and drink! I don't own any pet, and I don't really like dogs and cats, but it's still a living being. I'm sad that Jii had to suffer like that. It's lucky that someone kind adopt it.