Yonsei rhymes with:
fiance, gainsay, alexei, fiance, gainsay, gyosai, hearsay, isay, keisei, taisei
Yonsei sounds like:
yahnke, yamaguchi, yamaichi, yamaichi's, yamanaka, yamanouchi, yamasaki, yamauchi, yamauchi's, yamazaki, yams, yancey, yancy, yanes, yanez, yang, yanick, yanik, yanis, yanish, yank, yankass, yanke, yankee, yankee's, yankees, yankees', yankey, yanko, yankowski, yanks, yannick, yannuzzi, yawning, yawns, yeamans, yemen's, yen's, yeoman's, yeomans, yeung, ying, ynez, yniguez, yom's, yonce, yong, yongue, yonke, youmans, younce, younes, young, young's, younge, youngs, younis, yuan's, yuma's, yummies, yung, yung's, yunich, yunis, yunk