This presentation aims to propose how bimodal bilingual interactions become ordinary practices through co-enrolment at a secondary bimodal bilingual school in Hong Kong. The sign bilingual co-enrolment education programme/手語雙語共融教育計劃 (SLCO) was launched in Hong Kong to nurture deaf and signing sub-communities. In SLCO, deaf and hearing students are co-enrolled in the same classroom. Two teachers use both signed and oral and written languages to teach. Students learn Hong Kong Sign Language and thus sign or bimodal bilingual education. The previous studies in co-enrolment focused on the linguistic aspect and paid less attention to the social and semiotic aspects (Tang et al., 2014). Therefore, by taking an ethnographic approach this study seeks to enrich the previous studies on deaf-hearing interactions from the semiotic perspective (Kusters, 2017). It examines the environment where signed modality is its spatial repertoire (Pennycook & Otsuji, 2014) and how this environment shapes their daily interactions.  The study ultimately investigates (i) the use of multimodal semiotic resources at SLCO and (ii) how co-enrolment or “gungyung/共融” is realised and contested. Ethnographic fieldwork was conducted at an SLCO secondary school, consisting of lesson observation, participant observation with video recording at recess and extracurricular baseball practices, focus groups with students, and semi-structured interviews with teachers. Data are transcribed in ELAN and analysed based on thematic analysis (Braun & Clarke, 2022). The results show that diverse multimodal semiotic resources both enable and disable interactions at school. Also, “gungyung” is realised not only by direct interactions but also by being together and deaf and hearing students taking each other for granted. This presentation argues the importance of sharing a space in which signed modality comprises the spatial repertoire to enhance mutual understanding among deaf and hearing students.