It was around noon and school war about to end. Mob walked the halls, and he suddenly heard a beautiful, rhythmatic noise. He heard it from the band room, and when he took a look inside, he found you---playing the guitar.

That was how Mob met you. That was also how he figured out the wonders of guitar. You offered him lessons for free, and he gratefully accepted despite his masters, Reigen's, warnings.

In which, he met with you in the band room whenever he wasn't working, so you can teach him how to use a guitar. Of course, he wouldn't dare tell you about his powers or abilities. Albeit, he was starting to really like you.

"S-so.. like this?" Mob murmured while putting his fingers on the strings---trying to get the correct placement whilst holding the guitar. He was quite nervous and had an embarrassed blush on his face.