Looking for a series where childhood friends are living together think parents are away so they stay together in mean time

like Taiyou no Ie ?

⊂(・﹏・⊂)

There's also Parallel, I think. It's been a long time since I read it, but I thought the pair are childhood friends. The boy loves the girl, confesses to her, and she tells him it's impossible with a sad look on her face. He goes home depressed to discover that his dad is getting remarried, to her mother. Now they're off on a year-long trip to decide on various things, and he's stuck living with his love, who apparently will soon become his stepsister.