Toradora!: Bentou no Gokui

Ryuuji Takasu takes pride in preparing good bento lunches, so seeing Yuusaku Kitamura arrive with an extravagant homemade meal hits him harder than it should. What begins as harmless envy becomes a personal contest, and Ryuuji starts escalating his lunches to increasingly ridiculous levels just to prove he can do better.

His obsession eventually reaches the point of bringing a rice cooker to school. Then Taiga gives him a batch of badly made, overly salty rice balls, and Ryuuji realizes why they still matter to him. A bento is not valuable because it defeats someone else's cooking; the feelings placed into making it are what give the meal its meaning.