Literally a Saturday morning show ( airing at 7 AM JST ) it tells the story of Mari, a middle schooler, and her friend Waka as they travel to different times in our history and meet some of the most influential inventors in human history while trying to find Mari's dad. The show is aimed at children so don't expect any mature themes from it, but it's still well made and fun enough that it can be enjoyed by everyone. This also means the show avoid the usual anime cliché tropes and instead gives us a very likable cast of characters who are very fun towatch and easy to like.

As I mentioned above the show revolves around Mari a middle schooler who's dad has been missing for three years. Before leaving, her dad gave her a necklace that, as it turns out, is a part of a time traveling machine. By pure accident Mari ends up traveling back in time to 1600 and meeting William Gilbert, who amongst other things tells her that he has met her father. The show then revolves around Mari traveling back and forth in time to unravel the mysteries of the time machine and find her time traveling dad.

The show strongest point is the characters, all of them very likable, and the appearance of several inventors and their stories and interactions with the cast, as the show likes to show not only the inventions but give you some personal information about them, like how Bell invented the telephone because of his work with the deaf ( as his wife was deaf ) which helps give their inventions context and makes it feel less like just a history book and more like a proper story.

Animation wise the show is quite well done and while it's not going to blow your mind, it's always consistent and you won't see any QUALITY. What's noteworthy in the visual aspect is the excellent reaction faces the characters use when they are surprised, sad, etc. Maybe it's because it's aimed at children but this aspect is very well done and their faces are all very expressive and funny to watch.

The music in pretty average, it doesn't really stand out but it's never intrusive. The VA work is quite good with lots of familiar names. Overall the audio aspect of the show is slightly above average.

The show also has small clips at the end of each episode where they show a real life video of one of the inventions featured during the episode and give small explanations on how they work.

Overall the show is quite easy to enjoy if you want something that's pretty relaxing and funny, especially if you like to see time travel stories that feature historical figures related to electricity and magnetism.