I’ve heard this song twice during my trip in Japan on the radio. I’m assuming it’s popular because I heard it on the radio both times.
It’s a male singer singing in Japanese with an acoustic guitar, as far as I can remember. I think the chorus has the words “ichi ni” in the first part of it. I’d describe the melody of the chorus as notes going down steps for 2 bars then going back up for the next 2.
It doesn’t exactly sound like “love yourself” by justin bieber but it has all the same components (minus the trumpets) and I’d place it in the same genre.