Moe Chronicle

"Bumping Scratch" is the mini-game where you try to fill up a gauge by touching the monster girl in the right places and in the right way, using the Vita's touchscreen. You can do Bumping Scratch at the inn with any girl you've rescued from the dungeons, and if successful, it will increase her intimacy gauge (the 8 hearts). Each attempt costs between 250-400 BP, which you earn from fighting battles, but you can do a free practice that won't increase intimacy if you want to learn the right spots. A star effect will appear when you find the right spot, though it can be hard to see with your finger in the way. You can either tap quickly, touch slowly, rub, or pick (using both fingers). You will get hearts if you are using the right touch in the right spot, or stars if you have found the right spot but are not using the right touch. Stars still fill the gauge, just not as quickly.

There are three "phases" to Bumping Scratch, and each girl typically has two or more sensitive spots in each phase. The first phase lasts until you fill the gauge about halfway, then you have to find a different spot. The second phase lasts until the gauge is about 90% full. Phase 3 is the final 10%. During each phase you can trigger "Nude Flash" by alternating between two sensitive spots, using the correct touch (hearts rather than stars). Activating "Nude Flash" fills the gauge much quicker.

You will unlock trophies for doing a successful Bumping Scratch 10, 50 and 100 times. There is no visible counter to keep track, so just keep doing it and the trophies will unlock eventually. If you want to earn them faster, it's generally easier to succeed with the monster girls you encountered early in the game. Also, touching the right spot in the right way raises the gauge the fastest, but any action on that spot will still raise the gauge, just slower. In some cases it is advantageous to simply tap the spot repeatedly, as the correct method can take too long.

Note that the initial Bumping Scratch you played to recruit the girls into your party doesn't count toward these trophies, as it does not increase intimacy. You will need to do this 100 times at the inn.