The Zero-Sum Original Anthology Series features themed oneshots from various mangaka that publish in Ichijinsha's Zero-Sum and Ward magazines. Volume 10 theme: Conflict and Secret Societies.

1. Ranpo-sensei Laughs Like This by Takayama Shinobu
2. Secret Mission by Saeki Yashiro
3. Fang by Kawazoe Mariko & Nakamura Sachiko
4. Black Swastika Army by Katagiri Ikumi
5. Mushroom and Kappa - A Fierce Conflict of Honourable Men by Magami Guriko
6. Boys’ Cavalry by Kayase Shiki
7. Rindou by Asada Yasuka
8. Hideout by Sekka
9. Un Orso by Mizuhara Kenta
10. Be Enthusiastic, Father! by Inui Miku
11. A Promise by Seno Tatsune & Takamiya Aya
12. Let’s Meet at the Secret Society by Kinoshita Sakura
13. Will O' the Wisp by Kouzuki Leo
14. The Village of the Secret Agreement by Ueda Shinshu
15. At the End of an Endless Desire by Akai Higasa
16. Demon King Time by Kanou Ruri
17. Messenger of Justice ★ Moonlight Organisation by Usaki Hitomi

Sakura Hayato is a fairly normal high-school student. Except for one thing: ghosts are attracted to him.

On his 17th birthday, as his ghost problem reaches a peak, he encounters a sly-looking blond man in fancy black garb who introduces himself as "Undertaker Riddle." Riddle offers to help Hayato with his ghost problem on the condition that Hayato become his partner in the undertaking business, which is responsible for sending earthbound spirits to their destined place of final rest by way of a special funeral service. Though he initially refuses the suspicious proposition, circumstances soon come to pass where Hayato has to either accept a soul bond with Riddle... Or lose his life.

Accepting the post of Royal Tutor at the court of the king of Granzreich, Heine Wittgenstein is a little professor with a big job ahead! Each of the kingdom’s four princes has a rather distinct personality. Does their diminutive new instructor have what it takes to lay down some learning?

After losing their parents at an early age, Natsuhiko and his younger brother Tomoharu had to be separated. Years later, Natsuhiko opens a cafe as per his and his parents' dream. After an incident with a customer, he finds out that Tomoharu now works as a host! Not only that, but Natsuhiko has racked up plenty of debt to finance his fledgling business. Can he overcome these obstacles while convincing Haru to come back and keep the cafe - and their dream - alive?