The fanfic starts with Zuko asking Ty Lee for help getting Azula out of her shell. Their past attempts have either ended in violence or silence, so Azula's family turns to Ty Lee, in hope that her past connection with Azula can break through to her. Ty Lee is in the area for a few weeks so she figures it can't hurt to try. After all, she really wants to see Azula get better and be redeemed. But the path to redemption is not an easy one.
The sequel, Aphelion, has also been completed.
Restraint and Aphelion provide examples of:
- Abusive Parents:
- Ozai was emotionally and physically abusive to both his children, as well as sexually abusive to Azula.
- Ursa neglected Azula in favor of Zuko. She's trying to make up for it, but her relationship with Azula is still tense on both sides.
- It's implied that Mai's parents were emotionally, if not also physically, abusive.
- Alliterative Family: Azula and Ty Lee's child is named "Azusami".
- Babies Ever After: The final chapter of Aphelion revolves around Ty Lee giving birth to her daughter Kazumi.
- Calling the Old Man Out: Azula calls Ozai out for his past abuse and then burns him in the face.
- Dark Fic: Both stories are more dark and mature than canon. They deal with topics of domestic abuse, infidelity, sexual abuse, mental illness, and murder.
- First Period Panic: A flashback shows Azula getting her first period at twelve. Because her mother left years ago, no one told her about it and she thought she was dying.
- Generation Xerox: Due to her background, Azula has a hard time showing affection towards her child. As a result, she acts neglectful towards her. Ty Lee intervenes in an attempt to stop Azula from being like Ursa.
- Has Two Mommies: Near the end of the fic, Azula and Ty Lee try for pregnancy a year into their marriage. Azula has a firebending daughter named "Azusami".
- Heavy Sleeper: At the start of the fic, Azula sometimes spends all day asleep due to her mental illness.
- Mistaken for Cheating: Invoked. Azula lied to Ty Lee and stated that she cheated with Katara. She keeps up the lie for years because it's easier than explaining the truth.
- Parental Incest: Ozai began abusing Azula at age thirteen. Mai's parents suspected it and Ursa learned it after returning home, but it's otherwise a secret Azula prefers to not think about. However, the abuse really messed with Azula's ability to have romantic relationships.
- Parental Neglect:
- As a child, Ursa thought that Zuko needed her more than Azula so she all-but ignored Azula. It got worse as Azula grew and became more like her father.
- Because Ty Lee has many siblings, her parents were too busy for her growing up.
- Due to her own difficulties with her family, Azula has a hard time bonding with her daughter Azusami.
- She's All Grown Up: Restraint takes place five years after ATLA. Azula doesn't miss how Ty Lee has grown since then, and neither does Ty Lee miss Azula's developments.
- The Shut-In: The story starts with Azula having shut herself in her bedroom for who-knows-how-long. Ty Lee is asked to help coax her out.
- Slash Fic: Restraint is a Tyzula fanfic.
- Sleepy Depressive: At the start of the story, Azula doesn't do much besides sleep all day.
- The Talk: In chapter 17 of Aphelion, Azula's six year old daughter Azusami asks her how her other mother is pregnant if Azula was gone for two years. Azusami thinks that Azula and Ty Lee made her. Azula has no interest in explaining everything to her daughter, especially since Ty Lee's pregnancy is a touchy subject.
- Villainous Incest: Azula's abusive father sexually abused her from age thirteen to fourteen.