Tsugumi Ohba is the pen name of a renowned Japanese manga writer, best known for the highly acclaimed Death Note series, created in collaboration with illustrator Takeshi Obata from 2003 to 2006. The series has achieved monumental success with over 30 million collected volumes in circulation.

The duo's second series, Bakuman (2008–2012), also garnered significant attention, boasting 15 million in circulation. In 2014, Ohba teamed up with My Little Monster creator Robico to produce the one-shot "Skip! Yamada-kun." Another collaboration with Obata, Platinum End, was serialized in the monthly magazine Jump SQ from November 4, 2015, to January 4, 2021.

Despite the popularity, the true identity of Tsugumi Ohba remains shrouded in mystery. Rumors suggest that Ohba is a pseudonym, possibly belonging to Hiroshi Gamō, known for the manga series Tottemo! Luckyman. Another speculation links the name to Yuko Asami, a Shonen Jump artist known for titles such as Wild Half and Romancers.

Ohba's character, "L" from Death Note, is believed to mirror Ohba's enigmatic persona, particularly the character's love for snacks, unique thinking patterns, and distinctive sitting posture. Ohba's public communications often feature an avatar of a woman holding an apple, further fueling speculation about the author's identity.

As per the profile in VIZ's graphical novels, Ohba's hobbies include collecting teacups and developing manga plots while sitting in a unique posture, a trait shared with the character "L" from Death Note.