Chandigarh is already a city of planned gardens, and the Japanese Garden adds a different visual language to that grid. It has pagoda-style shelters, lanterns, water features, bridges, bamboo, and a tunnel linking its two phases, all arranged as a gentle walking park rather than a formal botanical collection.
It is not as essential as the Rock Garden or Rose Garden, but it is a pleasant change of pace if you are in Sector 31 or want a quieter local green space. Go early or late in the day, when the light is softer and the garden is being used by walkers rather than treated as a photo stop.