A 41-year-old man presenting with new-onset effort angina was referred to our clinic. Angiography revealed a left main trifurcation lesion including significant stenosis in the unprotected left main coronary artery (ULMCA), ostial left anterior descending artery (LAD), ostial left circumflex artery (LCX) with grade 3 collateral flow from the right coronary artery, and diffuse ramus intermedius artery (RI) (Supplementary Video 1). After an 8-French extra backup guiding catheter with a side hole was engaged into the left coronary artery via the right femoral approach, plain old balloon angioplasty (POBA) was performed from the ULMCA to LAD, LCX, and RI, respectively. Optical coherence tomography (OCT) demonstrated successful POBA for ostial LCX; thus, percutaneous coronary intervention (PCI) was planned with the 2-stent culotte technique from the ULMCA to the LAD and RI, rather than the crush technique, because 3 strut layers should be avoided on the ostial LCX (Figure 1A). A 3.0×38 mm everolimus-eluting stent (EES; Xience Sierra^®, Abbott Vascular) was implanted from the ULMCA to the RI. Subsequently, a 3.5×18 mm EES implantation from the ULMCA to the LAD was achieved with the culotte technique. After stent optimization with kissing balloon inflation and the proximal optimization technique, the final angiography showed no residual stenosis (Figure 1B and Supplementary Video 2), and post-stenting OCT demonstrated a minimized neo-carina between the ostial LAD and RI (Figure 1C) and two strut layers from the distal left main trunk to the shaft including the ostial LCX (Figure 1D-J).