I enjoyed this light school life shoujou manga. It's one volume and originally ran in Sho-comi. It's short and sweet. Both characters are likable and not sickening sweet. There is also no drama of a third party intentionally misdirecting the main characters either. Everything is done artlessly and with a lot of humorous moments.
There's nothing to this story though. Nothing really deep. But it's enjoyable. Mahiro is the oldest of her three siblings and pretty much is the one responsible for running their household and earning the money to support her family. She is also the top honor student at her school but unfortunately, she has to work in secret as it is against the rules to work as an honor student. She deals with her rival Hinata who disparages her and calls her a nerd who studiously works on her studies and doesn't enjoy life, not knowing that Mahiro is secretly supporting her family. She risks discovery when he inadvertently bumps into her while she is working. Luckily, she is in costume, makeup and not very recognizable from her everyday look. And he's smitten. So, we can guess what pretty much plays out here.
It's fun. I enjoyed it. I also get a big kick out of the English title used in the other editions. Secret Time or Secretive Hour is the more direct translation but My Nerdy Girl works too ;)