Rural children in South Korea exhibit higher foreign language anxiety and lower English competency. For such marginalized contexts where local communities cannot support children's learning, we propose and explore a new pedagogical approach, CRAYON (Community-based RelAY Online educatioN). In CRAYON, a pool of non-professional tutors take turns to meet and teach rural children in short relay sessions through mobile technologies. It uncovers and promotes volunteers' internal willingness to participate in community-based teaching, which could otherwise be fragmented and dormant in their tightly-woven daily lives. It greatly lessens the barriers to participation from multiple dimensions, i.e., time, space, and expertise, and encourages interested volunteers to easily join without taking much burden. As such, the approach can create new learning opportunities and help rural children overcome their motivational and environmental hurdles. Tutors could approach each child and share short but precious time with her; helping her experience repetitive and sufficient exposure to the language, each time with a newly met tutor. We conducted a short relay session-based English learning program for 5 rural children for 4 weeks in South Korea with 15 tutors. From the field deployment, we find that the rural children and the undergraduate tutors engaged in effective interactions and scaffolding, despite the constraints of partitioned short sessions. A particular pattern of interaction, i.e., continuous learner engagement support, emerged as they drew out the interactions over a short period of time. It was highly encouraging to observe that all children, including those who were disengaged in their classroom environments, actively participated in the CRAYON sessions. The findings elicited from the study have important implications in multiple dimensions. They suggest the possibility of extending the scope of learning environments to include first-met tutors and learners beyond re-established relationship. In a larger perspective, the findings imply a new direction to overcome the challenges of low childhood literacy in under-resourced areas. With adequate and sufficient support from educational institutions and CRAYON, this study argues that volunteer tutors with less experience can deliver effective instruction by sharing just a short period of time, and help a child who has been lagging behind the pace of the school catch up and re-engage.