Nijiiro Alchemikan ~Magic of Alchemy~

Yudai is in his second year of a magic school, living in the school's dorm. He enjoys his school life with his classmates, Touka, Ayane, Rinko and Hikari. One day, Touka says to him that she will be able to make gold. "I'll let you know when I make it!" But, she needs his semen to make it. After twists and turns, he finally gives her his semen. A while later, she makes a seed that will bear gold fruit. But, what the tree bears are some rainbow color oranges. Are they just oranges, or...?