Huh. I'm not sure, but I will make a guess こｎ (Kon) is most likely short for Konnichiwa (source) There are other meanings for it, but I think is probably the case.
Tontontonkatsuton (とんとんとんかつとん) is a drumming noise, like badabada tap dah (Similar to the Kuchi shōga of a taiko drum) I'm not sure if it has any other meaning or connotations in context though... but it's likely a way of applauding. It can also mean "badabada tonkatsu dah" or something XD;;
Re: Some words
こｎ (Kon) is most likely short for Konnichiwa (source) There are other meanings for it, but I think is probably the case.
Tontontonkatsuton (とんとんとんかつとん) is a drumming noise, like badabada tap dah (Similar to the Kuchi shōga of a taiko drum) I'm not sure if it has any other meaning or connotations in context though... but it's likely a way of applauding. It can also mean "badabada tonkatsu dah" or something XD;;