With the exception of cherry trees, Tokyo isn't really fame for being flower city. After the plums in February come the cherry blossoms in March, then the azaleas, the wisteria, hydrangeas then irises. It's kind of a set menu. Wandering around the local neighbourhood, many, perhaps most, houses have pot plants outside their home. In the absence of a 'real' garden, Tokyoites take pride in maintaining their colourful pot plants - you don't tend to find dead stalks on a plant. It's these unheralded flowers of Tokyo that inject life and colour, taking an edge off concrete grey. Many shops also have flowers out the front and local governments put time and effort into maintaining hedges, parks, and gardens. No-one seems to steal them; perhaps even would be flower thieves appreciate how bright and happy they make a megopolis look :)
A rice / sushi shop in Yanaka, not a flower shop as it might appear .