Ken appears in the OVA with Rosetta in the short "The Amazing Attempt at Diabolo" where Ken tries to learn diabolo basics from Rosetta herself. But during the performance, Ken's constant daydreams about him and Sora blind him and sometimes causes Rosetta to say some hurtful things in front of Ken and causes the audience to laugh while he whines. Ken's cluelessness also causes him to fumble some of the basic moves Rosetta teaches him and is billed for Rosetta's performance (Kalos figured that since this was for Ken, he should be the one billed). His last line before the short ends is him crying for Sora.