Shinkonsan!

From Pink Litchi Scanlations:

They were 6 yrs. old when they met. The one who would break Takara’s peaceful days to pieces was a transfer student from the city. Despite constantly fighting, twenty years later, they ended up getting married?!

His partner, Saionji Kyousuke, is a stubborn, self-confident man who hates people. He says ‘hate’ a lot even though he is a handsome man, but Takara can’t leave him alone and knows that deep inside, he has a pure heart.