Who's the Liar? is the sixth chapter of the Servamp manga series.
Mahiru and Kuro are at Misono's house as Mahiru tries to call his weapon. He keeps trying, but is unable to do it. Mahiru reflects over how Misono is teaching him how to be an eve-- a Servamp's master. Misono explains that the lead, the eve's weapon, can control the Servamp. Misono tells Mahiru that as an eve, Mahiru will have to learn how to control both his Servamp and his weapon. Misono tells Mahiru that Servamps were born to fight and that Kuro is lazy because Mahiru is weak. Lily asks Mahiru why he wants power and Mahiru says because he wants to protect his friends, who are his real family since his parents died.
Mahiru tells Misono that he will bring his friends, Ryusei, Koyuki, and Sakuya, there to meet Misono. Misono tells Mahiru not to mention his friends and to keep them out of this. Mahiru says that Misono would like them and that family and friends are worth fighting for. The lead on Mahiru's wrist begins to glow and Mahiru wonders if he really is too weak or if Kuro is just lazy.
At school the next day, Sakuya is absent. Koyuki says he has been missing a lot of school, so Mahiru and the others wonder if he caught a cold. Mahiru calls Sakuya, but there is no answer. He decides to visit him after school while thinking that he was acting strange the last time they were together.
On the way to Sakuya's house, Mahiru thinks about when he first met Sakuya in the fourth grade. Mahiru then gets confused, thinking that they met in middle school. Mahiru says that Sakuya also lost his parents and suddenly forgets where Sakuya lives, even though he has been there many times before. Through fragmented memories Mahiru thinks about how he and Sakuya have been friends forever, but questions it. Mahiru's head begins to hurt and Mahiru wonders if it is actually true that he and Sakuya have always been friends.
Sakuya then comes from behind Mahiru and grabs his shoulder, snapping Mahiru out of his thoughts. Sakuya asks Mahiru what he is doing in the area and Mahiru asks Sakuya where he has been. Sakuya replies by claiming a vampire attacked him so he holed up at home. Then he asks Mahiru if what he said was true or false, making a joke of it. Mahiru yells at him for making up another fairy tale.
In the distance, a scream is heard and Mahiru wonders who it was. Sakuya grabs Mahiru and leads him down an alley. Mahiru questions him, but Sakuya tells Mahiru to relax because they are friends.
Sakuya brings Mahiru to a cleared area and tells Mahiru to trust him and tell the truth. Mahiru asks him if he is okay and Sakuya answers by asking Mahiru if their friendship is a lie.
String appears from above and tangles Mahiru and Kuro, tying them up. Then, Berukia arrives announcing that it is time for the slasher show. Sakuya calmly tells Mahiru that he warned him about the vampire. He then yells at Mahiru over and over that he warned him. Kuro tells Mahiru that those two, Sakuya and Berukia, are Tsubaki's servants.
Mahiru, hurt and confused, asks Sakuya why. Sakuya, to Mahiru, ponders if the world started only five minutes ago and that all his memories are really only five minutes old. He then asks Mahiru what if he gave him false memories and that they only became friends five minutes ago. Sakuya asks Mahiru to remember what he told him when his mother died. Mahiru does not remember Sakuya being there. Sakuya asks if their friendship is a fairy tale.
Sakuya tries to strike Mahiru with a knife, but Kuro shields him and gets stabbed by Berukia. Mahiru asks how Sakuya can be a vampire. Sakuya says it's amazing and 100% true. He says that people believe little white lies and that Mahiru needed a friend.
Sakuya asks Mahiru why he didn't tell him that Kuro wasn't just a stray cat and that if he hadn't lied, he might still be his friend. Mahiru answers that he was only trying to protect Sakuya and keep him save from vampires. Sakuya takes this as Mahiru not trusting him and says that their bond is broken.
Sakuya says that the lies are making him feel sick all over and that their friendship will never be the same. He says that he knew Mahiru was lying but kept quiet about it. He says that he should never trust a human, they might kill you.
Mahiru thinks that he and Kuro will survive despite being attacked. He pictures an image of Kuro attacking Sakuya in his mind and dislikes it. He then turns his attention to Kuro, who has been stabbed with two swords by Berukia. Mahiru tells him to drink his blood. Kuro tells Mahiru that it will not help because Servamps get power from the will in a person's blood, and Mahiru has none. Mahiru is conflicted as to whether he should protect his friend or hurt him.
The string binding Mahiru suddenly breaks due to Misono and Lily arriving to save Mahiru and Kuro. Misono tells Mahiru to back off and that this is his fight. Mahiru tells Misono to stop and that Sakuya is his friend. Misono tells Sakuya that the two of them probably will not get along. Mahiru is conflicted as to who he should be protecting.