The classic "senior/junior" dynamic mixed with forced proximity creates instant chemistry.
If you want to dive deeper into this anime or similar series, secret mission sennyuu sousakan wa zettai ni ma top
: Based on the adult manga by mothica (also known by titles like Motto Aeide! Sennyuu Sousakan wa Sex mo Oshigoto desu ). secret mission sennyuu sousakan wa zettai ni ma top