MTL - Please Start Your Show - Chapter 101 The 101st Raiders:

At 18, Alex Kain is whisked away to Eryndor, a game-like realm where he gains 'Skill Synthesis', a talent to fuse skills into godlike powers. Battling monsters and conquering dungeons, he builds a harem of strong women drawn to his might and charm. With the power to return to Earth bearing incredible resources, Alex faces a growing threat that endangers both worlds in this epic of adventure, romance, and ambition.

The first time I realized that I ‘couldn’t die’ was during a practical training exercise in my third year as a hero cadet.A beast suddenly leaped out of the bushes and tore into my neck.‘How did I come back to life?’Yes, I came back to life. I didn’t die.And now, after hundreds, even thousands of years, I was still alive. Only I had survived.“But now… it’s finally over.”After wandering for millennia, I thought I could finally put an end to this long existence…“Dale! Dale Han! How dare you sleep during my class? You’ve got some nerve, don’t you?”“…Huh?”But what awaited me at the end of my long existence wasn’t a period, but a repeat sign.

Based on the popular Vocaloid series, by HoneyWorks, called “Kokuhoku Yokou Renshuu (Confession Rehearsal)“:

Natsuki, a third-year at Sakuragaoka High School, who holds unrequited feelings for her childhood friend, Yuu, who’s in the Film Club. However, instead of being honest about her feelings, she makes him be her confession “rehearsal” partner. Unable to say her true feelings, things start to get complicated when Miou and Akari, who are also in the Art Club, get involved! Will she ever be able to confess for real!?

The summer I was 17. A painting I created was sold. For 1.4 billion won.