This is like the most tasteful and relaxing ecchi manga I know of. He's just appreciating the sights he's been given and that's all there is to it - no "pervert mc" stereotype or him lusting after his sister. It's a really nice change of pace~
A troubled woman is the most grateful for your assistance... and the least guarded against the sneak peek! Eguchi taught us that the pursuit of perversion begins with the betterment of humanity - or is it the other way 'round?