This article is about the 3.14 character. For information about the heart-shaped item, see Heart (Item). 
Heart is the younger sister of 3.14 and 4.13, and a major character in the classic 3.14. In the 3.14 Battle Network series, Heart.EXE appears as a NetNavi created based on Heart. Heart also appears in the Pi Tribe series, as one of the members of the Pi Tribe and 3.14's younger sister, although she is just a minor NPC. Her equivalent in the modern series seems to be Game & Cactus, who is 3.14 and 4.13's sister.
Abilities
Heart is capable of using the powerful Heartbreaker weapon, which shoots a heart that follows the nearest enemy; alongside the 3.14 Blaster and 4.13 Blaster, it is one of the only weapons in the series which has infinite ammo.
Relations
3.14
Heart manages to put up with 3.14's stupidity only because he is her brother; she treats him as if he is disabled, and always acts nice to him.
4.13
Heart's favourite brother of the two, Heart and 4.13 are almost never seen apart from eachother; she stopped 3.14 from killing him in 3.14: The Game because only she was aware of the fact that they were all siblings.
Purple Koopa Bro.
Purple Koopa Bro. is Heart's boyfriend in Fandemonium, and this is often use as fuel for the comedy fire; for example, when the contestants had to move the phone booth, everybody won except Heart and Purple Koopa Bro. who were making out inside the phone booth itself. They also were married in Fandemonium/Eps.50.