And if you're wondering (even though you probably weren't) o, pyra does not try to convince esper to wear a bikini. Since she loves her sister so much, she respects her opinions and lets her have her own thoughts like hating bikinis.
Esper kinda has the same issue. Although she does wear a sports bra which is the most revealing she'll get, and she mostly wears it because it's basically a short tank top and she loves tank tops.