Ao no Miburo

These two anime series take place around the complex period of the early Meiji era. Although Rurouni Kenshin is more action-packed than Ao no Miburo, the two shows share a strong similarity in their medieval setting, with samurai/ronin, and idealistic main characters. In addition, both feature the Shinsengumi/Wolves of Mibu (Saito Hajime is present in both series). 

Both depict the rough gang of boys that protect the kids and elderly in your neighbourhood because authorities couldn't care less to do their darn job. Both share the same vibe of camaraderie, as a lonely, white-haired guy finds unexpected friends in this team of idealistic misfits. While the Wind Breakers are high school delinquents that kick ass, Miburo is a band of ronins (a ronin is a samurai without a master) living in late medieval Kyoto, protecting the city in the midst of complex geopolitics. Miburo is a bit deeper, psychologically, though the animation is not as advanced as Wind Breaker's 

set in the same time period and has the same theme of samurai in late tokugawa shogunate difference is hakuouki is marketed towards female and has female "observer" character 

Same theme of a young boy joining a group of swordsmen in late Edo Period Japan