They always present a polite and kind face, quietly protecting their charges. Can appear dense to others, but these are intelligent characters who note details and quirks and file them away without letting others know they're doing it. They would prefer having the mysterious stranger who showed up in the first episode come live with you, just to find out their real intentions. Or they'll casually suggest you go visit that abandoned field where a ghost is supposed to haunt.
Keeping the peace and serenity of the group and household is what prevents them from outwardly doing things, since they seem the type who could be very dangerous and create chaos if they wanted to. Anyone pointing this out (usually a villain or very smart character) will be met with a pleasant and suspicious dismissal.
Very commonly a character's mother or grandparent, this often overlaps with the Harem Nanny. Compare Silk Hiding Steel for a similar pleasant-yet-powerful personality and indeed this trope may be their role in the household.
- Sanae in Happy World! is immediately but quietly suspicious of her nephew's sudden Magical Girlfriend. She also puts down (violently) the perverted advances of her daughter towards other characters.
- Katsuhiko/Yosho in Tenchi Muyo
- Shigure in Fruits Basket is a skilled, albeit always well-intended, manipulator who uses Obfuscating Stupidity to his advantage.
- Aunt Haruka from Love Hina. Though unflappable in the anime, the manga shows her making a quick and uncharacteristic exit from Kanako, and a full blown loss of temper at Seta.
- Tomokazu's cousin Nanase in Yumeria.
- Akiko in Kanon.
- Kasumi Tendou of Ranma ½ is practically the prototype of the trope: She's the only member of the cast (regular or extended) who doesn't have some sort of major mental issue (or three).
- Watari of Death Note.
- God, the dorm leader in MariaHolic. She holds an iron grip over the dormitories, and occasionally shows mercy towards her students, but is definitely smarter than she lets on. Everything is accounted for.
- Kisuke Urahara from Bleach is not phased by anything and will steer The Protagonist (or others) where he wants them while they think it was their idea. All the while he will pretend to be a silly guy in clogs. He effortlessly trounced Yami
- Mr. Deerfield, Christine's all-purpose butler, from UFO Baby. He is the one containing Evil Chris when her fits get out of hand, serving as a reverse Berserk Button.
- Isabella from Paradise Kiss.
- Miya Asama, the Team Mom in Sekirei. Though she maintains a cool charm, sekirei familiar with her are terrified of her power, and she can make herself understood without losing her arete.
- Mikael from I'm Gonna Be an Angel! fits this trope to a T, mostly in regard to Noelle even going evil later on in the series.
- Raphael, on the other hand, while may not look like it at first glance, is this trope (albeit well-intended) to Mikael.
- Moominmama of The Moomins, who even in the face of the numerous magical happenings around Moomin Valley barely ever shows the slightest surprise, concerning herself with housework first and foremost. This even extends to when she herself gets shrunk down to miniature size, and she comments that she'll have to cook smaller portions for dinner from now on.
- Butler from Artemis Fowl, who stands by his charge no matter what. Come fairies, interspecies war, magic, or time travel, he will always have Artemis' back, reacting calmly (after maybe a wry quip or two) to whatever craziness Artemis is involved in this month.