The quest is unlocked after completing the Each Step Like Thunder scenario.
"Master Kohga plans to take a hot bath so he can boil away every particle of imperfection and achieve his truest, manliest form. But he needs something to fend off dizziness...and a cool drink!"
"Master Kohga worked up a good sweat soaking in that hot water, and then enjoyed a nice, refreshing glass of milk! Aah... One step closer to perfect manliness!"
- Master Kohga: Bonus Combo