Henkutsu na Yankee-kun wo Hottokenai

Shiki Mikagura, who is a yankee but has excellent results, and Yamato Touji, who is tall and blunt. When Mikagura almost fell down the stairs, Touji rescued him, and this is how the two met. They grow close after that, but one day Touji's blunt words make Mikagura angry. That night, Touji dreams of being attacked by Mikagura, and to find out why, he attacks Mikagura while he is taking a nap...

(Source: Kadokawa, translated)