The spring 2016 anime series 12-Sai was one of just a handful of shows that didn’t get a simulcast pickup as everything went down this season.
The manga from Nao Maita previously had a short-form eight episode OVA series.
The anime adaptation has a lengthy name attached to it as well with 12-Sai: Chiccha na Mune no Tokimeki, which is translated as Age 12: A Little Heart-Pounding.