Misa Amane's stalker

This unnamed character stalks and nearly kills Misa Amane.

Appearance
He has short hair and small, dark-colored eyes and wears a pair of glasses.

Plot
Misa Amane is walking when suddenly a man she has never met before jumps out at her and professes his love. He mourns the fact that she will not be with him, and so he tells her that he will commit murder-suicide. This is to be the way Misa Amane will die; however, Gelus, a Shinigami who has been watching Misa for some time through an observation hole, has developed feelings of love for her. Since he loves her, Gelus had been watching to see how Misa would die and sees that he can prevent her death. Gelus writes down the name of Misa's stalker in his Death Note, specifying that the man drops the knife and walks away. The man does this and dies of a heart attack immediately after. Having broken an important Shinigami Rule, Gelus dies as a punishment, leaving his notebook behind.

Rem, a Shinigami who had been watching Misa with Gelus, curious as to how she would die, takes the Death Note and drops it into the human world for Misa to find, as she deems to be appropriate in light of the circumstances. Misa finds Gelus' notebook and eventually meets Rem.

Film series
In the Death Note film series, Misa's stalker is named Ryotaro Sakajo (坂城 良太郎, Sakajō Ryōtarō). He is introduced in the first film and is seen again briefly in the sequel Death Note: The Last Name.

Sakajo is the assistant director of Misa Amane's "Misa-Misa's Happy Sweets" cooking show. He is obsessed with Misa, first seen watching her filming. Off-set, Misa blows her nose and throws the tissue into a trash can. When Misa leaves, Sakajo takes the tissue from the trash and puts it in his pocket. He presumably follows Misa outside after she leaves the TV station, eventually causing her to flee.

In a sequence bridged between the two films, Sakajo corners Misa and brandishes a knife, stating that he wishes to reunite Misa with her family and die with her. Gelus, watching from the Shinigami realm, kills him to save Misa's life. In doing so, Gelus dies and Rem brings his Death Note to Misa.

Drama
In the Death Note 2015 television drama, Misa's stalker is named Tsutomu Yukida (裕木田務, Yuukida Tsutomu). Yukida is one of the security guards at Ichigo Berry's concerts. He develops an obsession with Misa, who's the lead singer.

When Ryuk tells Light Yagami that Misa only has a short time left to live, Light becomes determined to save her. He attempts to warn Misa directly as she leaves one of her concerts, but Yukida holds him back. Yukida then pretends to befriend Light, but he gives Light misinformation because he thinks Light's a threat. At the time that Misa's fated to die, Light goes to where Yukida told him Misa would be, but she isn't there. Light calls Yukida to find out what's going on, and Yukida responds, "I've been protecting Misa-Misa all this time. Misa-Misa is mine."

With Light out of the way, Yukida confronts Misa alone as she heads home. He attempts to catch her interest by telling her how he saved her from a stalker (Light), but she gets creeped out and tries to get past him. Yukida grabs her and insists that he'll protect her, but she struggles to get away, tries to call the police, and slaps him. Yukida yells that he'll protect her and pushes her in anger, making Misa fall backward down the stairs, knocking her unconscious.

When Misa wakes up, Yukida is dead beside her. At first, Misa thinks Kira's killed him. A red notebook falls to the ground, and Misa meets Rem. Rem explains that Gelus saved her by killing Yukida.

Light is later questioned about Yukida by his father and another officer. Light had tried calling Yukida back after their last phone call, and Yukida's phone showed the call, so the officer wanted to know if Light was involved in or aware of Yukida's attack on Misa. Light says he didn't know him very well, and they just exchanged numbers because they were both fans.

Since Yukida died of a heart attack during his attack on Misa, L later has Misa apprehended on suspicion of being the second Kira.

Musical
In Death Note: The Musical, Misa's stalker exists but is unseen. At the end of Act 1, Misa runs out onstage, looking behind her as though she were being chased. She sighs, apparently relieved that no one is behind her, and stumbles upon the Death Note.

At the beginning of Act 2, Rem explains that the stalker who had attacked Misa was killed by Gelus to save her life.