Postgraduate research students (Ph.D.) are more likely to feel isolated studying their own topic. Consequently, chronic isolation, i.e., lack of social interaction, brings negative impacts, e.g., dropping out from the research program. Nudge is a concept that proposes that subtle changes in the way choices are stated can intuitively guide citizens towards desired behaviors, i.e., focus on driving behaviors and decisions. Nudge deck, i.e., sending a personal normative message such as peer-review feedback and emails to students, increases motivation and effort, and this may also be effective for relationship building. It can be envisaged that zero-cost online peer-reviewing tools such as google excel/word (peer-review feedback and email reminders as personal normative messages) guide students to improve their relationships among i) work colleagues and ii) supervisors. SDT needs of autonomy, competence, and relatedness are needed for the students to be intrinsically motivated. To address these SDT need satisfaction in interpersonal relationships, we conducted a BPNSS 9-item scale questionnaire survey among n=35 students from nine countries (relationships with colleagues, n=17; relationship with supervisors, n=18). The result of the study has shown that they may have felt a sense of connectedness with the supervisors (more competency and relatedness level). In contrast, their autonomy level is higher when interacting with colleagues.