Family Discount

Family Discount (家族割り, Kazoku Wari) is the fourth episode of Season 2 of the Future Diary anime, seventeenth Overall.

Summary
Ai Mikami recalls her past: being abandoned at Sakurami Tower by her parents and taken to Mother's Village by Marco Ikusaba. The two grew closer at school and planned to marry at the tower where they met. However, she fell for a prank played by her classmates and was gangraped before Marco rescued her.

In the commotion he stabbed and killed one of Ai's assailants, and the girl stopped him from committing suicide out of regret. The two promised to stay by each other's side forever.

In the present, Marco and Ai take Kurou Amano hostage and head to higher ground, where First, Second and Seventh square off. Although Seventh apparently has the upper hand, Yuno tricks them into splitting up by using her decoy phone, and Ai ends up with her throat slashed.

Kurou escapes the falling tower with a parachute. His ex-wife, Rea Amano, who was notified of the situation by the police, sees him touch down and berates him for leaving their son to die. He is last seen with a knife in hand, growing agitated at her demands.

Ai, Yukiteru and Yuno are trapped underneath some rubble, and despite her pleas, Marco attempts to rescue his love. During this, he berates First for hiding behind Yuno while she fights, and Second for being domineering in her and Yukiteru's relationship. It is revealed that Marco has been impaled through the stomach and wants to get Ai out from the rubble to spend their last moments together.

With Marco, First and Second's cooperation, the rubble is lifted, but Ai has already bled out and died. Choosing to go down with the falling tower, Marco gives the teenagers his parachute and dies with Ai in his arms, stating this is what he wanted, just the two of them till the end. Her diary then rewrites itself showing she is happy Marco tried to save her.

While descending from the tower, Yukiteru states his plans to reunite his parents, and asks Yuno for help convincing them to get back together. However, when they touch down, Nishijima informs Yuki that his mother has been killed.

Muru Muru's Section
Muru Muru shows up in Seventh's shared apartment and chaos ensues when Ai thinks Marco is cheating on her with the demon. Muru Muru presents them with the Exchange Diaries, and is puzzled when they instantly make up, a far cry from what she learned from her dating sims.