『-Becoming Your Beautiful Cousin- 美人姉妹と入れ替わり生活』 is a novel game in which the protagonist has a gender switch condition from his grandfather's invention, and gets involved in various troubles while trying to find a way back to his original body.
A Bishojo Game released in 2017 under the "Noirsoft" brand has been reworked for the "PandaShojo" platform for players of various ages worldwide to enjoy.

◆Introduction
"H... How did I become a girl!?"
The protagonist had acquired a gender switch condition between his cousins from the mysterious experiments of his grandfather a inventor.
To return to the original body, he cooperates with his cousins but,
Although there are many problems to worry about, he began to feel the charm of living as a girl...

◆Synopsis
The protagonist, Yu Tokiwa, is a male student from a slightly unusual family with an inventor grandfather.
One evening, his grandfather who came out of the laboratory said this.
"It...It's done... The Warp Device is complete"
Together with his two cousins, Marina and Shizuku, they became test subjects.
However, it seemed to have ended in failure as not even a speck of dust had moved.
Until ...

The next morning, there was a feeling of unease.
My body feels different... and it's missing something... but it also has something it's not supposed to...
What!? I switched bodies with my cousin...!?

◆Characters
・Marina Tokiwa
"Yu. You're oversleeping too often. Are you slacking off lately?
A cool and stylish female college student with a sharp mind.
She is the eldest daughter of the Tokiwa family and is Yu's cousin.
She always acts coldly towards Yu,
but in reality she loves him dearly and can't be honest with herself.

・Shizuku Tokiwa
"Well then, I, Shizuku Tokiwa, will be the one to surprise Yuu Tokiwa."
She is an energetic student with a great sense of style, although not as good as her older sister Marina.
She is Marina's younger sister, and Yu's endearing cousin.
Unlike her sister, she shows her love for her older brother in a very obvious way.
She is always smiling and liked by many people.

・Kokoro Kurusu
"I've been making this since the beginning for Yu-kun, is it okay...?
A bright and kind girl from the same grade at school.
She lives next to the Tokiwa's, and is a childhood friend of Yu.
She loves Yu with all her heart but is unable to express it,
often goes around in circles, and suffering from the same fate.

・Yu Tokiwa
An ordinary male student from an unusual family.
However, he got involved in his grandfather's experiment, and suddenly switched bodies with his cousin.
With no one to consult with about the switch, he is constantly worried about being found out by others.

美人姉妹と入れ替わり生活 -Becoming Your Beautiful Cousin screenshots