Mirai no Mirai

Little Kun isn't too happy about the latest addition to his family. With the arrival of a new baby sister in the house, he worries his parents may not love him as much as they used to... But when a teenage girl shows up and tells Kun that she is his sister from the future, it may be that there's more to this new relationship than Kun ever could've dreamed!

(Source: Yen Press)