Yamada Tarou Monogatari (1996)

A smart, athletic, kind bishonen attending rich kids' high school, Taro Yamada seems perfect... except that he’s actually dirt poor, living in a shack with 6 younger siblings and a mother with no sense of money and a perpetually absent artist of a father. Taro’s main worry is putting bread on the table. He relies on bento (lunch boxes) that girls in love give him, works multiple jobs, and even has a "pet" dog for desperate times... Every day is a lesson in survival for the Yamadas.

Source: www.anisearch.com/manga/5106