This is one of Hokusai's “Hokusai Flower and Bird Art Collection” series, consisting of 10 works, and the paintings show how he tried to express not only flowers and birds, but also the wind and air in nature.
In this work, hibiscuses are flowers that bloom around August to October and bloom around the same time of year, and the language of flowers includes “delicate beauty” and “graceful.
The hibiscuses' petals are delicately drawn, while the leaves are vigorously drawn. Note the cute expression of the sparrows in motion.

Hokusai (1760 - 1849)　Japanese Woodblock Reprint
Sparrow and Hibiscus

葛飾北斎「芙蓉に雀」Katsushika Hokusai "Fuyo ni Suzume"