Heart Stars are items in Kirby's Dream Land 3. Kirby must collect all 30 from various characters in order to bring forth the Love-Love Stick to defeat Dark Matter. Some of the notable characters that carry Heart Stars include Chef Kawasaki, Samus Aran and Professor Hector (the creator of R.O.B.)
These magical items change their form between a star shape to a heart shape and glow between yellow and pink. They are possessed by residents of Dream Land who reward Kirby with them at the end of the stage if he does them a personal favor during that level. If Kirby manages to obtain all six heart stars for an area and then fight the boss, Dark Matter's influence will be lifted from that area, and if Kirby returns to that boss's arena, the boss will not attack and will simply allow him to leave (the only exception is in Iceberg, regardless, because Kirby has to beat King Dedede after he has obtained all thirty heart stars before facing Dark Matter anyway).
If Kirby replays a level where he has already received a Heart Star, his good deeds will instead be rewarded with a 1UP.
Common trends appear in the tasks that must be completed. The first stages of each of the five levels involve some action involving flowers or mushrooms. The second stages require the use of a Copy Ability or action to be used to accomplish a goal. The third stages have Kirby complete some mini-game. The fourth stages have items that need to be recovered. The fifth stages feature a friend of one of the Animal Friends. The 6th stages are varied and require either the discovery of multiple lost items (most notably the pieces of R.O.B.) or the shaping of a series of Star Blocks.