 If you liked
Isekai Yakkyoku
|
 ...then you might like
Toshokan no Daimajutsushi
|
Both main characters are strong boys with a good sense of morality, using force only when absolutely needed, since they rather want the best for everyone (except when they are unfairly accused of something bad).
*Both stories fill you with enjoyment
<>Toshokan no Daimajutsushi has a better built world, Isekai Yakkyoku has plenty of information about sciences and diseases.