UPDATE! This anime's English name is "One of Them is My Younger Sister!"
Genres: Romance, Comedy
After Shougo's father dies, he gets to inherit an company, but has to endure some training and find a girl to marry first. There's his half-sister from his school that wants to marry him, but a number of other girls also attend there, so he's unsure which one is her.
No clue if this will be legally streamed yet either.