An incredibly athletic older brother, Tenryu Taiga. A programming genius girl, Tenryu Fuyuki. Siblings separated for 8 years ended up living under one roof again, after facing the problem – a lack of funds for living expanses. Fuyuki proposes a way to earn money, a core system deeply involved in people's daily lives, a game that awards you money as a prize for defeating malicious bugs in cyber world, the 《Aries》 structure. Taiga relying on his inborn senses becomes a warrior in the game, is puzzled by the unfamiliar sensation of game world. One day Saionji Rui, Fuyuki's best friend appears and is attacked by a mysterious bug― “I'll be waiting, my prince.”. Hybrid fantasy battle of cheating siblings begins here!