Neon The Animation

Both are ONA that were made to promote a japanese city with cute characters. Both have three short episodes. Both are historical, but while Neon The Animation is slice of life, Shiroishi no Yousei Pichi is more fantasy. 

Short anime made as a promotion for a city, featuring duo city mascots as a main characters. Those mascots also happen to be cute girls. 

Both are anime with short, few minute long episodes. Both promote some city/prefecture. Both have animated as well as live action parts. Both are historical and slice of life genre. 

Both are short, few minute long ONAs that advertise some japanese city with the help of animation. Both feature live action sequences. While Honey Tokyo is sci-fi and is promoting Tokyo, Neon the Animation is more slice of life and is promoting Osaka.