As a new approach in the Integral Engineering Class (IEC) at Tsuruoka KOSEN (National Institute of Technology Japan), a joint PBL class of the second- and the fourth-year students was conducted, and the fourth-year students acted as facilitators in their group discussions. Fourth-year students are intended to support the second years’ discussions by supplementing their knowledge and experience, leading to deeper second-year student discussions. Furthermore, experience in teambuilding and leadership are expected to lead to the development of initiative in fourth-year students. The effects of the joint class were investigated using a questionnaire survey on self- and mutual evaluation. A preliminary analysis of the questionnaire results suggests certain positive effects from the group discussion process, such as active discussion, diversity of opinions, and summarized group opinions. We intend to continue improving the IEC based on the questionnaire results.