Interactions such as UML Sequence Diagrams and Message Sequence Charts are broadly adopted models for describing behaviors of distributed systems. They focus on specifying message exchanges between subsystems with rich choice and scheduling operators, and they are associated with an intuitive graphical depiction. This paper presents a Runtime Verification tool dedicated to distributed systems. This tool, called HIBOU, equips an interaction language with small-step semantics. The tool offers a functionality of Runtime Verification to analyze logs of system executions, captured as so-called multi-traces, against interactions. The tool also provides animation features for interactions that can be used to explain verdicts produced by the Runtime Verification.