Cherry works at an elderly daycare in the mall, while Smile's orthodontist is also located there. By accident, they run into each other and accidentally swap their phones, in something of a meet cute.
If this were a standard romance, you would expect them to go on dates and slowly grow closer to each other. However, this isn't that type of story - instead, they get sucked into the world of the past, trying to find a record that one of the elderly residents of Cherry's daycare has lost.
They soon discover that the record he is looking for was produced by his wife, a singer-songwriter. His past is inextricably linked to the mall, as a record pressing business used to operate there, which he worked for.
In the end, his story, and the story of the teenagers collide together, combining the weight of history with sweet hope for the future.
While I found this story highly satisfying, I think there are a few weak points:
1. The supporting characters aren't given enough time to make themselves likable. Cherry's family, friends, and Smile's family would benefit from more on screen interactions.
2. The story focuses on their exploration of the past, and not on their budding romance. Without context, it would be difficult to see that this is really an romance at all, since they spend most of their time as friends, and not as romantic interests.
3. As with most Japanese romances, there is very little epilogue - most of that is left up to the viewer.
I believe that if you adjust your expectations accordingly, you're in for a very entertaining time, but do be prepared for the feels, because there are a lot of them.
