The Cherry Fluff will self-destruct when provoked, causing AoE damage around where it strikes. However, if a Cherry Fluff has less HP when it reaches you, it will do less damage.
If you are further away from the Cherry Fluff, it will deal less damage as well.
Weaker Pink Fluffs - South of the Shrine
Normal Pink Fluffs - Near Taiko Drums (NW)
Stronger Pink Fluffs - North of the Shrine
There are also some aggressive Cherry Fluffs in Kat's Kokeshi Doll lair that only specifically target a player (the indication of this will appear as "Kill <insert player name>!" in the name of the Cherry Fluff while targeting it).
Cherry fluff also give orbs,try using fire rain on many of them.
This monster will call others for help. Careful around large numbers.
Cherry Fluff are particularly helpful for grinding, because they drop items as long as you've hit them, therefore AoE attacks in large groups will cause any Fluff hit to drop items when the self destruct.
"Sakura" is the Japanese name for cherry trees and their blossoms.
Since Cherry Fluffs have a self-destructive explosive attack and spawn in a Japanese-themed area, they might be a reference to the kamikaze suicide attacks by special forces in Japan during World War II. Alternatively, they might be a reference to cherry bombs.
Unlike other Fluffs, Cherry Fluffs have a glossy left eye in official art. The reason for this is still unknown.