Seishirou Klaus

Seishirou Klaus (倉臼 征史郎) is the head butler of the Sanzenin Mansion. He prides himself in being the chief butler. He is often seen with Tama. He disapproves of Hayate working for Nagi as a butler at first, because of his poor-looking face, but slowly starts to accept him as the story progresses. He is prone to random appearances, usually commenting on Hayate's incompetence as a butler, and also threatening to fire him. In most if not all scenes with Nagi he has appeared in, he has been attacked by her in some sort of way, usually with comical results. He also makes a short appearance with Tama in the Hayate no Gotoku!! OVA where he is blasted away by the possessed Nagi.

Story
Klaus first appears as the head butler of the Sanzenin Mansion, where he questions Maria over her letting Hayate work as butler for Nagi, and gives her two days to get rid of him. When Maria fails to do so, he confronts Hayate himself, citing that hiring a previously fired worker with no background was unacceptable. He gets into an argument with Nagi over Hayate's features, much to Hayate's chagrin, and finally stops after Maria suggests that he give Hayate an aptitude test, which Hayate passes.

A few days later, he appears crawling out from under Nagi's bed, commenting on Hayate irritating Tama, before he is mauled by Nagi and later Tama. He then watches at the window with Nagi as Hayate fights Tama, and threatens to fire Hayate if he loses to Tama. He is later berated by Maria and made to clean up the mess Hayate and Tama created.

He is seen instructing Hayate on how butlers are to be gentlemanly and that he should carry himself like a man. He later takes a walk in the Sanzenin garden and confronts Hayate, who he mistakes for an intruder, but falls in love with what he mistakenly thinks is a cute girl but is actually Hayate in girl's clothes. He is then knocked out by a hit on the head from Maria's broom.

He later appears with Maria in a panic after failing to find Nagi and Hayate in the mansion, after they had gone to Kujuukurihama to watch the New Year's sunrise.

He then appears after Nagi and Hayate's visit to her grandfather, Mikado's house, commenting that Hayate's main aim in life is to become a good wife, and a good wife for Tama at that, a retort to which Nagi replies by attacking him and accusing him of making Hayate a pervert.

Later, after Hayate brings Isumi to Nagi's mansion, and after he is shut out by Nagi, Klaus appears with a thermometer and declares that Hayate has a fever, after which he and Isumi stares at Nagi, putting the blame on her for Hayate's illness.

When Wataru and Saki visit the mansion, Nagi instructs Klaus to kick them out using all means necessary, so he sends robots to eliminate them.

Klaus later appears commenting on how all Sanzenin butlers should take the Hakuou entrance examination, to the surprise of Nagi who thought he was dead, and says that if Hayate fails the examination, he would be fired. He is present when Yukiji and Hinagiku visit the mansion to tell Hayate that he has failed his entrance exam, and comments that by supposedly passing the exam, Hayate actually became useful.

When the Delaz Fleet hijacks the ship Sakuya and Nagi are on, Klaus, Makita and Kuneida quickly defeats them, and comment about how they protect their masters with all their might, but before being berated by Sakuya for letting the Delaz Fleet on board in the first place. Klaus later saves Hayate from drowning in the winter ocean, and his cool attitude towards Hayate both flatters Hayate and dumbfounds Nagi.

Klaus appears again as Hayate is training Nagi to compete in the Hakuou Academy track meet, commenting on how Hayate is turning Nagi into a delinquent, before he is attacked by Nagi once again. He then threatens to fire Hayate if Nagi does not place first in the Hakuou Academy track meet.

When Hayate and Nagi place second in the Freestyle Marathon at the Hakuou Academy Track Meet, Klaus decides to fire Hayate, for failing to fulfill his duty to Nagi as a butler, but when Nagi threatens to fire him for letting the Delaz Fleet on board Sakuya's cruise ship earlier, he decides to send Hayate to the Butler Tiger Hole to test him.

After a prolonged absence, in which Klaus only appears twice, once on the omake page of the ninth volume, and once at the end of chapter 101 where he asks Tama if he still lives in the Sanzenin mansion, he finally appears on a huge television screen in front of Nagi and Maria, and then appearing on a smaller television when Nagi destroys the earlier one. He says that he had prepared for Hayate needing more time to study by getting a temporary replacement butler.

Klaus also appears alongside Nagi, Maria, Hayate, Ayumu and Tama when they are transported to a lonely mountain villa with a murder victim on the floor, and he instructs them to search around for Conan Santa.

Klaus again appears in Hakuou Academy when Hayate, Nagi, Izumi, Miki and Risa are having a normal story competition. He tells his story of having a stupid dog called Lucky who went missing for two days, causing him to search everywhere for him, but returned on the third day.

Klaus appears on a television screen informing Nagi that the painting she received was fake, just moments after Hayate claimed the same thing.

After another prolonged absence, Klaus is seen with Mikado, who wishes him a happy birthday, and boasts to Klaus about how he looks younger despite them being the same age.

When Nagi finally came back from their vacation, Klaus is informed of their situation regarding the Sanzenin inheritance. He met with Mikado to protest against Nagi being kicked out of the mansion but to no avail. He met Hayate who was searching for an apartment and gave him one that was given to him by Nagi's mother, Yukariko, once held a crush on Klaus as a child, as she asked Klaus to marry her, but Klaus declined saying that it was against the law to marry without presenting a gift that would shock the one being asked to marry. Yukariko gave him an apartment, but Klaus said that they can't get married because it didn't shock him as it had to be an apartment tower. As Yukariko went to knock it down to build a tower, Klaus said that he won't let her as it was now his property to prevent her from trying to get him to marry her.

Trivia

 * Klaus's seiyuu, Kenta Miyake also voices Kaibara from the Sore ga Seiyuu! Anime.