One type of task interaction that students in a foreign language class may do is using the language they are studying for discussion. This paper analyzes interaction among Japanese university students participating in such discussions in English. The participants are interactionally competent; one source of resources they draw on to construct this competence is their first language, Japanese. Participants occasionally use Japanese to refer to Japanese things. They also use Japanese in the pursuit of intersubjectivity, such as using Japanese to solve a word search, with this being designed as a solution of last resort. Also, participants typically go beyond intersubjectivity as they translate Japanese into English. Word search design and going beyond intersubjectivity make visible participants’ task orientation to English as the proper language to use in these discussions. This task orientation provides a means for understanding the institutionality of the interaction.