For as long as they've been siblings, Yu and Hina have been stuck together like glue. Hina is spoiled rotten in their household, given that she has full access to his games, his attention, and his space. But being her older brother, he can't help but dote on her despite her sometimes getting on his nerves.
By the end of the video, she's crying over a picture of her and another boy taken in middle school, apparently heartbroken, while quickly flashing back to her crush on the boy, his closeness with Natsuki, and Hina's confession to him. As yet another gesture of brotherly affection, Yu decides to cheer her up, and takes her outside to hang out.
In Project mirai 2, the song is Len's token song as it is here, but KAITO is given an alternate vocal track. The hoodies Hina and Yu wear look similar to the ones featured in the game and have a yellow or blue lining, referencing both Vocaloids.