| 高山 マリア|
|Height||146 cm (4'9")|
|Weight||33kg (72 lbs)|
|Job||Neighbor's club adviser/Special temporary lecturer|
|Family||Kate Takayama (older Sister)|
|School||St. Chronica's Academy|
|Japanese Voice||Yuka Iguchi|
|English Voice||Kristi Kang|
|Novel Debut||Takayama Maria (& Kobato Joining Flag ①)|
|Manga Debut||Chapter 12|
|Anime Debut|| Episode 1 (Cameo)|
Episode 4 (Official Debut)
Maria Takayama (高山 マリア, Takayama Maria) is a supporting character from the Boku wa Tomodachi ga Sukunai series. Maria is the supervising teacher and moderator of the Neighbor's Club and is a ten-year-old nun. While being exceptionally gifted in academics, she can also be very rude and immature, when annoyed. She develops a sibling-like relationship with Kodaka, who regularly makes her packed lunches, and is affectionate with him, also stating that she wouldn't mind marrying him when she gets older much to Kobato's annoyance.
The reason why Maria cannot make friends is that she is an immature child prodigy whose wisdom stems not as much from natural talent, as from an advanced education.
In Volume 8, it was confirmed by her sister, Kate, that Maria was never a nun nor a teacher, information which Aoi Yusa tried to use to disband the Neighbor's Club. In response to this, Sena appointed her as a special temporary lecturer for the Neighbor's Club, using her father's authority.
Maria has blue eyes and long lavender-silver flowing hair. Maria has been described as having snow-white skin. She is usually shown wearing her nun outfit, which consists of a dark-blue one piece dress with a white collar design of two long triangles and dark blue Cornette with a heart decoration. Maria also wears a necklace with a key.
During her trip to the Theme Park, Maria wore a white tankini with a cross. Maria also owns a white tankini swimsuit with her name sewn on it.
Maria is childish and displays this tendency numerous times, even when claiming that she's an adult. Due to Maria being a child prodigy, her arrogance made her unable to socialize with her peers.
Maria is both naive and gullible, a trait which Yozora takes advantage of. Due to Kate's taunting, Maria came to think that she was actually a teacher and an adult. This causes Maria to be very rude, as seen when she scolds the people around her (Yozora being the exception).
While she may not realize this herself, Maria really wants to befriend Kobato, to the point that she felt jealous about how popular Kobato really is with her classmates.
According to Kate, before becoming the Neighbor's Club's advisor, Maria was quite pessimistic. She feels a lot more comfortable in class than out of class. She says that she's real cocky with her grades and as such, has trouble making friends. Her ability to make friends has apparently gotten worse since she started skipping grades.
- Sister Maria
- Miss Maria (By Yukimura)
- Tool of God (By Kobato) 
- Church Lady (By Kobato) 
- Stupid Head (By Kobato)
- Hoe bag (By Kobato)
- Hooker (By Kobato)
- Hooker Overlord (By Kobato)
Maria is shown to be very intelligent in terms of high school Math and the Japanese Language. She does Yozora's homework and never complains about its difficulty. Maria even comments that Kobato's Math homework is "too easy", something even Kodaka was impressed with. Maria seems to have an advanced vocabulary, as shown when she is able to describe "Annexation" (The term of the incorporation of territory into another Geo-political entity) with great detail.
In contrast to her knowledge, Maria is extremely naive. She is routinely able to be outsmarted by many characters in the series and is extremely trustful of others. Even Kobato once managed to use Yozora's words to trick her.
Maria also doesn't seem to do much research on her Bible studies. This is shown when she didn't realize there's no such commandment as "If someone slaps you on the right cheek, give them your room also. Oh, and also sign the paperwork to officiate their club" (obviously made up by Yozora to coerce her into lending her favorite naptime quarters to the Neighbors Club.)
In terms of sexual education, Maria is also rather naive in this topic considering she has a high-school level education (although in another sense, Maria did skip grades and hence, it is possible that she was not taught these things).
Maria is quite gluttonous, being able to eat great amounts of food without getting full. In fact, one of the ways to get on Maria's good side is through food. At the festival, Maria is shown eating copious amount of street foods such as candied apples, Takoyaki, Fried Squid and more. At the theme park, despite eating many hot dogs and a crepe, Maria is still able to gorge down a plate of curry rice.
- Maria's surname, Takayama ( 高山 ) literally means "Tall Mountain".
- Maria was voiced by Yuka Iguchi, who provided the voice of Index in the To Aru Majutsu no Index series. Like Maria, Index is a nun-in-training, they also look and behave very similar to each other.
- In episode 5 of the anime, Maria takes on the form of a healer in the video game Romancing Saga XIV, which greatly resembles Index's Walking Church attire.
- Maria's surname, Takayama and her Catholic background may also be an allusion to the famous Christian-Daimiyo during the Sengoku (Japanese warring states era) period, Dom Justo Takayama.
- The meaning of Maria's given name in Hebrew means "sea of bitterness" or "sea of sorrow." Some alternated meaning may mean "rebellion" or "wished-for-child". True to this, Maria's past is indeed rather bitter due to her attitude. Also, it could describe Maria's rebellious attitude. Kodaka comments in the manga that it's fitting that a nun is called Maria. This is because the first Catholics to set foot in Japan were from Portugal and so the Japanese for Mary is Maria just like in every country with Catholic influences.
- Maria's favorite food is potato chips and she also seems to have a liking for Nikujaga (Japanese Meat and Potato Stew).
- The Neighbor's club-room was originally used by Maria for her afternoon naps.
- It was first mentioned that Maria is the one in charge of the Neighbor's club club-room. This later is proven to be false, and officially, Kate is the one in charge of said room.
- Although in the anime, it was depicted that Maria was rude and constantly insults Yozora when asked to use the club-room before Yozora had enough of it and slapped Maria. In the manga and Light Novel, this event never really happened and hence, placed Maria in a better light than perceived in the anime.
- After Aoi's and Kate's proclamation of Maria never becoming a nun and a teacher in the first place, the latter is just as confused and shocked as her fellow club members.
- It was noted by Kodaka that Maria has larger breasts than that of Kobato's, much to the latter's chagrin.
- Like with Kodaka, Maria is also a fan of the manga adaptation of the "Romance of the Three Kingdoms" series, where her favorite commander is Zhuge Liang, until Kodaka preached her of the achievements and merits of Zhang Liao and Wei Yan. As a result, Kodaka and Maria now share the same favorite commanders in the said series.
- She makes a cameo in chapter 40 of the manga Kämpfer with Yozora and Sena. She, alongside Yozora, is seen teasing Sena in the locker room.
- "I prayed to God that God would kick the crap out of this cross-dressing freak that time he made me eat that weird food that tasted like medicine, but now it's different! Thank you, Yukimura!" (Maria, while hugging Kodaka, badmouthing Yukimura for the force-feeding but also thanking her for changing her ways afterward.)
- "It's like white poop!" (referring to the bubbles formed by bath soap)
- "poopy head!" (referring to someone she is insulting)