Social comparison experiments in two different social conditions, competing between friends and between strangers, were carried out with 88 Japanese male undergraduates. Participants were asked to come to the laboratory in friend pairs to participate in the experiment. Two pairs were randomly combined for each experimental session. In the Between-Friends condition, one of the two pairs solved 20 anagrams competitively while the other pair observed them. In the Between-Strangers condition, one performer and one observer were randomly chosen in each pair and the performers solved anagram tasks competitively. As in our previous study, the anagram tasks were presented utilizing a presentation trick so that one performer-and-observer group viewed easier anagrams than the other group without their noticing the difference. As intended, those who viewed the easier anagrams outperformed the others, becoming winners in all sessions. No participants noticed the trick. After the task, all four participants rated the ability of the two performers including themselves. Their ability ratings showed that they tended to evaluate their own ability modestly. Even winners consistently rated themselves lower than the others rated them. Two possible explanations of why Japanese participants made such modest responses were presented and discussed.