"Us" probably refers to the unisex character of the fragrance - and I can actually imagine it on both men and women.
More so on women, as the sweet fruit bubble gum note is, in my opinion, rather feminine.
But it would probably work well on young men too.
With this bubble gum tone, "Us" comes across as casual and "cool" without being cold.
Sandalwood and vanilla make it nicely creamy - but not as soft ice cream creamy as This is her! which remains my favorite - although "Us" fits well into summer.
The musk in the dry down leans a bit towards the mature side - but overall "Us" remains youthful - which I don't mean to imply that only young people should wear it.
Even "young-at-heart" individuals will enjoy this friendly summer fragrance.