Sue-chan, the youngest of the Mitama family, has a weak constitution. Manami and her triplet sisters are always worrying about her. On the other hand, Himeno's niece, Shino-chan, isa very curious girl. She asks Himeno all kinds of questions as they go for a walk, and looks adorable doing it. All the little ones—Himeno's niece Shino-chan, as well as Manami's triplet sisters and baby sister Sue-chan—live their own stories.
When all sides are triangles,
 it's called a triangular pyramid.
عندما تكون جميع الجوانب مثلثة
.فإنّها تدعى مثلث هرمي
Ein Körper mit vier dreieckigen
Flächen heißt dreiseitige Pyramide.
Si todos los lados son triángulos,
es una pirámide triangular.
Si todos los lados son triángulos,
es una pirámide triangular.
C’est une pyramide
si chaque face est triangulaire.
Quando tutti i lati sono triangoli,
si chiama piramide triangolare.
Se todos os lados são triângulos,
é a pirâmide triangular.
Когда все стороны треугольные — 
это тетраэдр.