One Piece: My Crew is from Other World - Chapter 7: Changes in Mood

If video game currency is to exchange with real life currency, then it must have a powerful economic entity to guarantee the exchange rate. Furthermore this entity is none other than a country’s government. But why would a government guarantee the ability to exchange video game currency with real life currency?

War can also be fought with currency. Winning victory without firing a shot is a way to topple a country. A game where real money can be exchanged, a super money-making machine. Its name is [Zero] and it is a financial explosion from head to tail.

- Description from Novelupdates

A seemingly ordinary training exercise led Chen Jian and his squad into a completely different time and space.In the post-apocalyptic world, monsters run rampant, and the surviving humans struggle to live under their terrifying claws.To fight the monsters, the living have abandoned everything.Human nature no longer exists; beastliness is the mainstream.To defeat them, one must first become them.-----------------Chen Jian was supposed to be like the others here, pursuing the maddening evolution.But, when the tungsten-core armor-piercing round first penetrated the Kui Niu's keratin armor, he suddenly discovered...Perhaps there is another way to stay alive?

After 20 years of dedicating his life to opera ever since he had quit the performing arts high school, he had failed at an interview. Losing his motivations, Jo Yunjae depended on alcohol to live out his days until one day, he had been sent back 20 years in time, to the day before his high school admission.