Why are all the heroines in the novel Pisces?

Because Pisces is a romantic fantasy constellation.

Pisces, a sweet girl, is really suitable for Marisu. All the men in the play love him and spoil her, satisfying Pisces' imagination of love and the world.

The date of birth of Pisces is 19, from February to March 20th, in the zodiac, east of Aquarius and west of Aries. The main stars are Jupiter and Neptune. The representative color is sea blue.