Japanese Thanks

The Japanese tend to equate gratitude with a feeling of guilt. In many cases where Westerners would use expressions of gratitude, apology expressions (Sumimasen) seem to be the most appropriate means in Japanese (e.g., upon receiving a gift) (Coulmas,1981, p.82).

Japanese verbal behavior exhibits an exquisite sensitivity to mutual obligations, responsibilities, and moral indebtedness. There is a large range of routine formulae in the language for apologies and thanks and speakers are expected to make extensive use of routines with little variation (Coulmas,1981, p. 88).

Japanese thanks and apologies do not necessarily call for a response. If there is no real issue between the parities, apology expressions can pass unacknowledged without implying any offense. A major function of a response in such cases is to make communication inoffensive. In other cases in which a response is appropriate, the most common strategy then is to deny the guilt implicit in the apology (iie, iie, do itashimashite) (Coulmas,1981, p. 89).

Reference

Coulmas, F. (1981). "Poison to your soul": Thanks and apologies contrastively viewed. In F. Coulmas (Ed.), Conversational Routine: Explorations in Standardized Communication Situations and Prepatterned Speech. The Hague, the Netherlands: Mouton Publishers.