Kamiya Hiroki has always thought women have it easy. This thought is only reinforced by his lazy 24-year old sister, who spends all day playing games. He always asks himself why he couldn't have it easy. Why he couldn't be a girl. His wish was granted when a mysterious reader of his blog told him on about a way to swap bodies.
After successfully swapping into a girl's body he proceeds to have a less-than-spectacular time, but the real trouble begins when he finds out what the person who swapped into his body was up to...
This series provides examples of:
- Action Girl Mikuriya Mikuni.
- Ax-Crazy: Kirishima Sachi, who massacred his own family and is currently imprisoned. Subverted when the protagonists met him in person, that he immediately proved to be a valuable and helpful ally in their investigations despite the initial hiccups. Then Double Subverted when X's true identity is revealed: 'his insanity given form and life'
- Brown Note: Kirishima Ai's Cross Ability is to put anyone hearing her singing to sleep, at her mercy.
- Enemy Without: What X really is: Kirishima Sachi's insanity given form and life.
- Everyone is a Super: Everyone has a special power that is manifestation of their true desire. However, the soul acts as a Power Limiter that prevents this power from actually being used, not unlike a square peg in a square hole. The Cross Method replaces the soul, resulting in a square peg in a round hole; this mismatch allows the power to leaks out and actually being used in a practical way.
- "Freaky Friday" Flip: What the Cross Method allows.
- The Ghost: We only get to see Kamiya's father's hands, though if Kamiya's words are any indication, they have the exact same face.
- Murder Is the Best Solution What Mikuriya suggested about how to deal with the stalker.
- No-Sell: Kamiya's Cross Ability is Unsleeping Guardian, which makes him immune to Ai's Brown Note.
- Parental Neglect: Kamiya's father left him alone with his sister to go on a business trip. Turns into Abusive Parents and Parental Incest with Offing the Offspring when everything's revealed in the final chapter.
- Reality Ensues: When swapping bodies with Mikuriya for the first time, Kamiya doesn't take into account that he had become a famous teen idol whose face would be recognizable to most passersby, and thus attracts a lot of attention by wearing bright clothes that only serve to attract more attention to himself (granted, not out of a desire to actively be noticed, but more to experience wearing girly clothing); this is contrasted by Mikuriya's choice of less conspicuous clothes when out in public in later chapters, often wearing a cap or hoodie to easily conceal her identity.
- "Shaggy Dog" Story: They spend a majority of the manga to track down 'X', the prime suspect for the case. Then it's revealed that X had nothing to do with Kamiya's sister's murder, and that it turned out to be her own hand that killed her own physical body, and that the culprit for that particular case turns out to be their own abusive father.
- Slave to PR: Mikuriya to a point she suggested murder to prevent a scandal.
- Stalker with a Crush Kamiya met one while in Mikuriya body.
- Stuffed into the Fridge Literal and figurative example in one: Kamiya did this to his own sister.
- Suicide, Not Murder: The final chapter revealed that Kamiya's father entered his sister's body to kill Kamiya, while his sister entered his own body. But thanks to Kamiya's Unsleeping Guardian, his sister fought off the assault, to the point of mortally wounding her own body. It's practically murder, suicide and Heroic Sacrifice at the same time.
- Teen Idol: Mikuriya Mikuni.