Hyuuga-san.it's "conceit".
Hyuuga misspoke 慢心 as 漫心 (both are /manshin/) - 漫 (the first kanji of manga) and 慢 ('ridicule/lazyness') are both /man/ but you'd not see 漫心 in Japanese much; Google even corrects it to 慢心 for you in searches.Well... that's how it goes...It's conceit, Hyuuga-san.It's not "cornseat",