You’re Nina Iseri, So Who Am I?

Isseri Jin is a hired musician in an amateur band, a chosen gig worker who's been ground down by life for years and has mastered every trade under the sun. In his twenties, he lands a job at the Toyokawa Group, only to be assigned to work under the person destined to become its future president. He leads a life that's both successful and unsuccessful, all work and no rest. Then... he transmigrates. He's back to being a strapping seventeen-year-old kid. On the day he first arrives in Tokyo, the sky still isn't very blue, and the water isn't exactly green, either. At least his lungs, not yet invaded by nicotine, get to enjoy the benefits of a fresh start.

"Got you, thief! Give me back my luggage!"

Stroking his burning cheek in disbelief, Isseri Jin looks at the pigtail girl who's a head shorter than him and just slapped him. He immediately makes a major decision that will change the course of his life: hit her back with exactly the same force!

In my own dream, you think I'm going to let you bully me???

(Male protagonist, band harem, GBC + Bocchi the Rock! + MyGO!!!!!/Ave Mujica)