In a manga, a smartphone could fall in love by being personified and encountering experiences that trigger emotional bonds. It might interact with other objects or characters in a way that mimics human romantic connections.
It could be a hit depending on several factors. A unique plot, well-developed characters, and quality illustrations could all contribute to its success. However, competition in the manga market is fierce, so it's not guaranteed.
A mean guy in manga might fall in love when he realizes the person he's been mean to has qualities he truly admires. Maybe it's their bravery, loyalty, or just the way they don't back down from him. This realization can trigger a change in his feelings and lead to love.