Novel functionality in condensed matter physics is continuously attracting huge attention owing to the possible novel future applications including quantum computing, electronic devices and so on, leading to continuous discoveries of new materials and phenomena. This is part of these efforts in our research project to explore the novel functionality in quantum magnets. Here we propose to investigate a newly synthesized unusual honeycomb magnets with a strong magnetic frustration by using neutron diffractions with magnetic fields. Our goal is to examine the competition between magnetic order and magnetic fields, searching for a new quantum phase and studying its relevance to the polarisation. This will give an opportunity to deepen our understanding of its magnetoelectric property, which could provide new ideas for designing new functional materials and applications.