The Delinquent Shimizu-san Sitting Next to Me Has Dyed Her Hair Black

「Shimizu-san, you dyed your hair black.」 「Ah, yes.」 「Why did you dye it all of a sudden?」 「Because…yesterday…」 Shimizu-san, who sat next to me and had dyed her hair from blonde to black gradually lowered her voice, slightly blushed, and laid her face down on the desk. — Description from novelcodex.org