Assendelft is the name of a town in the Netherlands, and floral art (flower painting) originated there.
Atelier Blumen offers the same floral art course (headquartered in Roppongi, Tokyo) taught by Hisayo Katsurada, who learned floral art techniques in the Netherlands.
Classes are held mainly in Kitakami City, Iwate Prefecture, Japan.
For you who are concerned, you can experience what Lesson is like by actually trying it out.
Starting with basic brushwork, students will progress through the basic course, the main course, and the research course, painting seasonal flowers on a variety of everyday objects.
Upon completion of these courses, students may become instructors.