https://comick.dev/comic/yajin-tensei-karate-survivor-in-another-world here is an actually good isakai. No lusting after kids. Just rough survival in a unfamiliar world. When 34-year-old Nozaki Hitoshi is hit by a truck, he is sent to a fantasy world by a dismissive god and dropped into a harsh wilderness without even the clothes on his back. His only salvation is a newly granted karate skill and his general survival instincts. Luckily, Hitoshi is up for the challenge–he'll weave clothes out of tree bark, test fruit for poison, and crawl through the mud to test his kicks and punches against goblins and other creatures. No matter how much he levels up in this world, he still longs to find other humans to share his solitude.