He's definitely not as strong as Atsushi or Chuuya, but he's strong enough for this, and the support of the wall and her own strong limbs definitely helps as he holds her up, pressing her back against the cool brick. Mikan starts to fumble with his buttons, and Dazai's not about to stop her; there are bandages wound around his neck, bandages that cover part of one shoulder as they continue down to encircle his chest, but the shoulder she manages to reach is bare, bare enough for her to find skin instead.

She is desperate, isn't she? And he might be a sadist, but it would really be absolutely cruel to prolong this anymore. And he doesn't want to. So as he returns that kiss, he shifts her slightly in his arms, the tip of him pressing at her already slick entrance, pressing inwards. "Tell me if it hurts, Mikan-chan," he breathes, and then kisses her again, kisses her breathless as he pushes upwards, shuddering faintly at the sensation.