This is a serious topic. You shall immediately recognize the connection between Ohba, Tsugumi and Ryuuk, the first page shows you a black silouette holding an apple. Ryuuk LOVES apples as well. Ohba looks like a rocker, with vastly larger/wider torso than legs, but we’ve seen women on that body type as well, it looked a bit unnatural. If this were in EDO, I’d noticed a pronounced chin as well. But I’m no Sakata Gintoki, so I don’t mind.
The story runs in real time with the publication, characters have birth dates and live and die in real time with the publication of the story in Shonen Jump. Other noticeable thing are the shoes and legs of “L”, in chapter 2, page 7, there are several scenes based on photos, and these shoes and legs tell me the same thing: Ryuuk or some kind of a rocker. There is also one rocker on the team who made music for the Death Note, named Taniuchi Hideki, there is a weak connection between him and Hideki Ryuuga, just by the name and the photo in chapter 2, page 7. I’d have to look into him deeper later.
Ryuuk is dressed, sits, stands in a position like a rocker, dressed in leather. The wide shoulders, thinner abdomen also force him to sit/stand like this. This analysis is only valid IF Takeshi Obata, the illustrator knows Tsugumi Ohba personally, in person. Since those two did the Bakuman series, which is about two boys who decide to make a blockbuster manga series from scratch, I think it is entirely possible they’ve know each other personally for a long, long time.
So, what is with this cute, girlish identity of Tsugumi Ohba? Is it a character created by a man, or is it his alter ego in the virtual space? Or is it really a woman? The only hard evidence is to meet in person. But from what I’m seeing with an eye unclouded, I think that Tsugumi Ohba has an assigned gender at birth as a MALE, but has developmental and mental features not purely masculine, likes to get lost in thought, and has ‘androgyne’ features. *note: I am using that word only on the basis on being told about someone to be an androgyne*
If this were the Edo in Gintama A.D., I’d look for Tsugumi Ohba in the Saito bar in Kabukichou. But I’d have to go trough all the people even vaguely related to Takeshi Obata. I can assume that Tsugumi Ogba is between 170-190cm tall and the characters of L and Ryuuk have been loosely based on him. Quiet and thoughtful when in the thinking mode, cheerful and childish when in love. Unusually long hair, white face, prominent, long chin, some facial hair growth, slender, thin arms and legs. White face is made more prominent with dark pigmentation under the eyes. Language knowledge and thinking skills: we can assume that understanding of English is at some useful level, but has consumed a LOT of literature in the japanese language.
So, Tsugumi Ohba, I will find you, I will hunt you down, and I’ll invite you for tea and CAKE. Lots of good cake. And chocolate. Chocolate with ginger.