.  No, Lum is very consistent in her affection towards Ataru and all of her anger is just. To qualify for tsundere streotype, the character must show excessively negative outburst to mundane matters by the other character. Ataru was publicly asking for sex to strangers, thus would have been arrested or beaten to pulp by someone else anyway, had Lum not intervened first, in a way saving him from legal troubles and furthur humiliations. Ataru is the lustiest(?) person in the universe, so it will take extraordinary force to stop him, so you can't really say Lum's lightening bolts are excessive.Ran is closest of Urusei Yatsura Characters to tsundere type. Of course, the person nobody wants to anger is O-Yuki Sama.  No, Lum is very consistent in her affection towards Ataru and all of her anger is just. To qualify for tsundere streotype, the character must show excessively negative outburst to mundane matters by the other character. Ataru was publicly asking for sex to strangers, thus would have been arrested or beaten to pulp by someone else anyway, had Lum not intervened first, in a way saving him from legal troubles and furthur humiliations. Ataru is the lustiest(?) person in the universe, so it will take extraordinary force to stop him, so you can't really say Lum's lightening bolts are excessive.Ran is closest of Urusei Yatsura Characters to tsundere type. Of course, the person nobody wants to anger is O-Yuki Sama.  