In the series, Yuno pretends to be a perfect model student on the surface, but is actually a yandere who is obsessed with the main male protagonist Yukiteru Amano, and kills unhesitatingly to protect him.

[6] In the anime adaptation, Yuno is voiced by Tomosa Murata in Japanese, and by Brina Palencia in the English version.

[8] In another interview, Esuno stated that Yuno is a character whose development of some facets and elements of her past would explain how she conditioned her current psychotic self.

But, this masks her dark and sanguinary side — a ruthless, cold and calculating psychopath who has little, if any, problem in using others for her ends: her and Yuki's survival.

She will resort to cruel and usually violent methods, most of the time coming out of nowhere, that generally end in bloody deaths, of either the Diary Holder or any respective follower, effectively making her a yandere.

[11] A year prior to the events of the series, Yuno becomes obsessively in love with classmate Yukiteru "Yuki" Amano, due to a promise he made to her to go stargazing together.

With nothing else to live for, Yuno decides to dedicate her entire life to Yuki, stalking him everywhere and recording everything he does in a diary on her cell phone.

Yuno, realizing that she really loves him, commits suicide to let him win the Diary Game, allowing him to become the God of Time and Space of the Second World.

She then uses her newly given divine powers to create a pathway to the Second World and finally reunite with Yuki as they prepare to fulfill their promise of stargazing together.

Like Gasai, the live-action Yuno is one of the Future Diary Holders, and she has a one-sided, stalker-like crush on male protagonist Arata Hoshino (a character based on Yuki Amano).

[22] Reviewing Future Diary, Jacob Chapman of Anime News Network criticized Yuno as being a "slavering yandere".

[23] The Artifice highlighted the depiction of Yuno and how she jumps back and forth from "just your average adorable middle schooler" to a "raging, calculated, cold-blooded killer".

Yuno can either be the competent protector for Yuki that handles issues with a cool head or just a pure villain that has fans screaming at their TV.