@Coffee 114 That's what I'm thinking too. Most of the 'challenges' Chika was throwing at Prez were mostly toys you could pick up at a dagashi shop (shameless Dagashi Kashi plug). Being pretty poor, Prez would have more exposure to these types of things either due to monetary issues or possibly due to his grandparents as he stated with the juggling. All of his more 'episodic' issues have all been more based around skills used in more social settings (dancing, singing, sports, etc), which he is less likely to have done if he spent most his time either studying or working as shown from how he has a relatively small social life outside the school.
Though it was absolutely hilarious to see Chika being 'cheated' XD I guess he can only be good when she WANTS him to fail.