Accounts of the social experience within livestreaming channels vary widely, from the frenetic “crowdroar” offered in some channels to the close-knit, “participatory communities” within others. What kinds of livestreaming communities enable the types of meaningful conversation and connection that support relationship development, and how? In this paper, we explore how personal relationships develop within Twitch, a popular livestreaming service. Interviews with 21 pairs who met initially within Twitch channels illustrate how interactions originating in Twitch’s text-based, pseudonymous chat environment can evolve into closer relationships, marked by substantial trust and support. Consistent with Walther’s hyperpersonal model, these environments facilitate self-disclosure and conversation by reducing physical cues and emphasizing common ground, while frequent, low-stakes interaction allow relationships to deepen over time. Our findings also highlight boundaries of the hyperpersonal model. As group size increases, participants leverage affordances for elevated visibility to spark interactions; as relationships deepen, they incorporate complementary media channels to increase intimacy. Often, relationships become so deep through purely computer-mediated channels that face-to-face meetings become yet another step in a continuum of relationship development. Findings from a survey of 1,367 members of Twitch communities demonstrate how the suitability of these spaces as venues for relational interaction decreases as communities increase in size. Together, these findings illustrate vividly how hyperpersonal interaction functions in the context of real online communities. We consider implications for the design and management of online communities, including their potential for supporting “strongbridges,” relationships which combine the benefits of strong ties and network bridges.