15 it’s funny. The banished prince is on his 3rd life (hero,sage and now prince). He wants to be incompetent so he doesn’t have to always work and save everyone and take it easy but his true power keeps getting revealed. The king is an idiot and doesn’t realize, banishes him - but a lot of competent people follow him to new territory. Where he keeps trying to be judged incompetent but keeps inadvertently doing miraculous things. Haha.
Sasensareta Munou Ouji wa Jitsuryoku wo Kakushitai