My fault. It is from the [REM9 (Hamiltan)] NamiRobi OneShota Vacance (One Piece) doujin page 2: [nhentai.net] https://nhentai.net/g/416776/ The speakers are teenage boys and I ended up going for 'Big sisters' and 'big sis'. I thought some dialogues like in page 29 would perhaps use the term 'Nee-chan' better since the boy here is teasing Nico Robin. Yet again I guess something like 'Siiss~" might work too. Thank you for responding btw.
You're welcome (IMG:[invalid] style_emoticons/default/smile.gif) For 29 I think even 'You/Your" is fine because it sounds natural in English.