Nomura Mizuki manga
An ordinary boy called Sherlock Doyle is captured and forced to put on his twin sister's dress by the Emperor's diplomat to be shipped to a small country called Ehren. His genius sister, Glinda, went missing two days before she's supposed to be sent to Ehren to be an royal tutor for the King's children. The sudden life change is too overwhelming for Sherlock, but he sees no way out. Later, he finds out the disturbing truth about the kingdom's intention with his sister.
Adapted from Light Novel series by Nomura Mizuki. Meet Kanoha Inoue, winner of a prostegious writing award at the age of 14. Mistakenly branded a "Mysterious Bishoujo Author" and subsequently vowed to never write publicly again. Meet Amano Tooko, self-proclaimed "Bungaku Shoujo". Eats up works of literature, literally. The two of them are the only members of the Literature Club. Each day he writes short stories for her to eat. Until one day Tooko arbitrarily decided to put up a drop box for anyone with a problem...
Our protagonist, Inoue Konoha is still being led around by his senpai, the Literature Club's President, self-acclaimed "Literature Girl" who loves stories so much that she can eat them, Amano Touko. One day, someone put in the Literature Club's "Love Consultation Post Box" a bunch of paper scraps that have the words like "Hate", "Ghost is" and a bunch of puzzling numbers on them. Calling the act as "picking a fight with the Literature Club", Touko once again got Konoha involved in her investigation; but when they found the culprit, this girl turned toward them, smile, then said "I'm already dead." The 2nd arc of the popular bitter & sweet school mystery series.
The story starts with the death of Hikaru Mikado. That guy was a natural charmer, a “harem king”, but had no real male friends. After he died, he became a ghost, a soul, but Koremitsu Akagi can see him. Koremitsu though, isn’t really like Hikaru. His red hair and his evil-looking eyes make him look as a delinquent, even though he is very kind inside. Hikaru asks him a favour: he wants to fulfill a promise, which he couldn't fulfill anymore. The promise was to give his girlfriend and fiancée, Aoi Saotome, 7 gifts for her seventeenth birthday. Koremitsu accepts, and has to work hard to help fulfill Hikaru’s promise with Aoi.