Ninjacompoop is an episode about Yumi being a ninja, but goes too far while being one.
Yumi gets bored so Ami gives her a quiz from her "Sparkle Teen" magazine, which is supposed to tell you which career you're best suited for. When Yumi is finished, the magazine says she should be a ninja. Yumi accepts that and she orders a ninja instructing monkey (which is activated by putting a special pill in water). The ninja instructing monkey is Master Ai Ming Pang. After hours of training, Yumi finally becomes a ninja, but she gets carried away as she pinned a fan on the wall after a concert, scaring away fans, and tries to spar with Kaz (which ends with Kaz having a leg cast and crutches and reaching for the door). Ami goes to Pang for help, but he is melting away. After paying $19.95 and activating the pill once more, Pang's partner, Master Son Son Blue trains Ami to be a ninja. Ami then tries to battle Yumi, but Yumi unmasks her and says that she could never hurt Ami because she's her best friend (plus Ami admitted that Yumi could easily beat her either way). Ami and Yumi then go home for their Post-Gig snack.
- This episode aired November 19, 2004 (Japan/USA/UK)
- This is the first time we see Ami and Yumi in their ninja costumes.