Kimi to Boku to Sekai no Hotori: Futaribocchi Christmas

Touya and Eiji were always almost like brothers since they were both little. They're five years apart, but they're best friends who have been together ever since. They both thought their relationship would continue as it always has, celebrating birthdays and spending Christmases together. That was until Eiji had to go to Tokyo to study to take over his father's company.

They were separated and meeting each other was a rare occasion now. Now they're in their third winter apart. Touya was excited to see Eiji for the first time in a while. However, he was kissed and confessed to by Eiji who had just returned?!

(Source: Kasakura Shuppansha, translated)