I’m the Brother of a Famous Vtuber, but When My Stepsister Forgets to Stop the Stream, Somehow I Became Famous

I have a little stepsister named Shiojiri Isuzu who is a hikikomori and brocon.
When she is at home, she is the cute little sister and is usually very close to me and says, “I can’t live without you, brother!”
The true identity of Isuzu is ‘Isuzu Wine’, a very popular Vtuber with 1.9 million subscribers.
She is a very popular and promising newcomer, who has risen to her current position within six months of joining the big Vtuber agency.
I, on the other hand, was a shady guy who was ridiculed and dumped by my classmate, Kisogawa Kusumi as a ‘dull and not good-looking guy’.
But one day, Isuzu forgot to turn off the stream and her chat with me was broadcast.
Isuzu, who is a cheeky little demon character in the stream, is revealed to be actually a kind-hearted girl and a brocon, who fights in the stream for her poor family.
I will be all over the world as the gentle brother of Isuzu, and I will even make my debut as a Vtuber!
Meanwhile, Kusumi, who dumped me when I became popular, is slipping away and regrets losing her place in both real life and online, but it’s too late.