Tensei Kenja no Isekai Life: Daini no Shokugyo wo Ete, Sekai Saikyou ni Narimashita

Yuji Sano is a hardworking office employee who spends long hours at work and at home. After his computer displays a message about being summoned to another world, he restarts it, unknowingly accepting the invitation. Transported to a fantasy setting, Yuji believes it to be a dream and hopes to return to his real life and pending tasks. His Monster Tamer class lets him befriend slimes, which provide him with large amounts of magical knowledge. This leads to him acquiring a second character class almost instantly. As Yuji gains immense power and becomes the strongest sage in the world, he must navigate this new reality while still thinking about his responsibilities back home.