Your life begins to change when you encounter a piece of underwear. Kei Fukatsu is a 34-year-old single temporary employee. Her dispatch contract is about to expire. Her boyfriend of seven years has never talked about marriage... She wonders if she will continue to live like this for the rest of her life, but when her friend recommends her to an underwear store, she discovers the perfect underwear for her. From the excitement she felt when she encountered her destined underwear, she takes a new step in her life.

“Regret ever underestimating me.” Arialein, the crown prince’s fiancée, devoted herself tirelessly to the nation’s prosperity through her daily duties. But one day, she is suddenly accused of false crimes and subjected to the unexpected cancellation of her engagement—followed by banishment from the kingdom. Given just three days before her exile, she vanishes without a trace… As schemes and ambitions intertwine, the stage is set for an unprecedented tale of vengeance and retribution! [Original Web Novel](https://ncode.syosetu.com/n3270iz/) [Original Web Serialization](https://comic-earthstar.com/episode/2551460909679245214)

Sixteen-year-old Martina is a count’s daughter who adores isekai reincarnation novels. She is engaged to Rudius, the second prince of the Kingdom of Alzrite. However, Rudius is a shallow womanizer. Martina has no love for him at all; longing for true romance, she spends her school days eagerly waiting for their engagement to be broken off. Then one day, Rudius undergoes a sudden and dramatic transformation. His long hair becomes short. His neatly worn uniform turns sloppy. He starts walking bowlegged. His sharp eyes glare menacingly at everyone around him. He even rides off on a stolen warhorse! “I’ve regained the memories of my previous life from another world. You bitch, our engagement is over!” Martina is suddenly informed by Rudius, who claims to be a reincarnator from another world, that their engagement is canceled. But for someone like her, who absolutely loves isekai settings, this is more than welcome—! https://www.cmoa.jp/title/356230/