She's the Cutest... But We're Just Friends! Volume 1 by Akamitsu Awamura

Kai Nakamura has the average range of otaku hobbies for a high school boy, but the buddy he shares them with is far from ordinary... Kai’s best friend in the whole world is Jun Miyakawa, his classmate known as a super hottie. Though Kai and Jun just met when they enrolled in high school, they hit it off with passion for all the same hobbies! When they’re together, the pair never have enough hours in the day. Kai and Jun can’t get enough of each other’s company as they chat about video games and manga or sing anime songs at karaoke. Love is fleeting, but friendship is forever in this "just friends" rom-com filled with flirty fun!