Board Thread:Questions and Answers/@comment-154.20.146.94-20160619221137/@comment-28290173-20160620023439

Tantou are quite hard to level up on day maps because their leadership is so poor. Most people I know trained their tantou during events where there wasn't a level cap for gaining exp (or the cap was really high) and the enemies were weak, for example the war expansion events' night maps, Floors 1-40 of the underground treasure chest events (NOT the easy one we just had, mind you)

If you're really desperate, heavy infantry has more troop HP and boosts their leadership so they won't lose the troop fast (but still fairly quickly). Sakura fubuki status will give their stats 20% boost so make sure you use that too

Another option is to train your wakizashi for 6-1 instead. I've made it past 6-1 without any tantou on my team at all and all I did after that is grind them on 6-2 since the enemies there are weaker and you encounter fewer yari. Your tantou don't need to be really high levelled to go there; about late 30s to 40s is sufficient.

Though tbh I found tantou to be hardly necessary at Ikedaya. Especially with the 6-4 final boss where it's a day battle, it's much better to train wakizashi instead (lots of people will argue otherwise though)

Good luck!