Athena is a daughter of the Tennousu family. She has mainly appeared in the manga. She has only been shown in the anime during a brief flashback where Hayate reflects on his first girlfriend. Her parents are presumed missing or dead, since she lived alone. She is Hayate's old girlfriend, as well as his first Mistress, whom he met 10 years ago. Since he was very young at that time, he called her "A-tan" for short.   
~!Her family owns Hakuou Academy, and she is the board chairman of the school. In the manga it's shown that she has feelings for Hayate despite being away from him for 10 years. Though when she meets him again she lies to him that he doesn't remember him anymore. Later on she leaves Japan for Greece and as she's about to leave Hayate confesses to her and she replies with a kiss and thus, Hayate and Athena kissed for the first time in 10 years.!~ In the 4th season she appears  more frequent and becomes one of the tenants at Nagi's dormitory.

It's never easy to be a gentleman's gentleman, but working for a girl who's not only not a gentleman but also a lightning rod for trouble (and not always particularly ladylike either) is a job that few butlers could handle. For Hayate Ayasaki, however, fighting off teenage heiress Nagi Sanzenin's would-be kidnappers is as much a part of butlering as serving the tea. Nor is that the only dangerous activity that Hayate's bound to be asked to perform during the course of the average day. Need to nurse everyone through an illness? Then that's part of Hayate's job description. Got an embarrassing video that has to be retrieved before it hits the internet or need help returning stolen money? Hayate's your manservant! However, as competent as Hayate may seem, there's one thing he's not particularly good at: noticing when pretty girls are attracted to him. Which is probably a good thing, as otherwise the silverware might never get polished! 
 
(Source: Sentai Filmworks)

__Non-anime roles:__
- Shenhe - Genshin Impact (VG)
- Sugar - Goddess of Victory: Nikke (VG)
- Dikke - Reverse: 1999 (VG)

The second season of Hayate no Gotoku!. 
 
Ever since he first met Nagi Sanzenin, Hayate Ayasaki's life has become increasingly more crazed and chaotic. Which is a bit of a problem, since, as the eccentric heiress' butler/personal bodyguard, he's theoretically supposed to be a stabilizing and protective influence. Unfortunately, Nagi and her friends attract trouble the way dropped lollipops attract dirt, and if Hayate has to take a couple of nasty licks along the way, that's just part of the job. The real sucker punch, though, is that Nagi's increasing attraction to Hayate himself is getting precariously close to transforming their professional relationship into something far less professional and much more like a relationship. Is Hayate up for the emotional perils of a round of "upstairs, downstairs"? Or will the purely physical dangers of life on Her Majesty's Domestic Service do him in first? 
 
(Source: Sentai Filmworks)

Hardworking Hayate has a plan to pay back the yakuza—who are now the legal owners of his body parts: he’ll kidnap someone and ransom them for a mountain of money! But things get tricky when his would-be kidnappee—who as luck would have it is the daughter of a mind-bogglingly wealthy family—mistakes Hayate’s actions for a confession of love, and subsequently hires him to be her personal servant. At least his employment future is secure, or so he thinks…
 
(Source: Viz Media)

Athena Tennousu