Even if Kaito's triggered ability triggers more than once in the same turn (perhaps because one or more attackers had first strike, multiple players were dealt combat damage by your creatures, or there were multiple combats), and you return an attacking creature to hand each time, you won't be able to activate Kaito's loyalty abilities more than twice that turn. That is, Kaito's triggered ability is not additive.

If you return a creature to its owner's hand with Kaito's first ability, you may activate a single loyalty ability of Kaito twice, or you may activate two different loyalty abilities.