After learning Nen and becoming a true Hunter, Gon returns to Whale Island with Killua. When he arrives, Mito has a box for him. She was told by Ging to give this box to Gon once he became a Hunter. However, it appears that the box cannot be opened.
Warning: file_put_contents(/var/www/17858778-cf11-4d06-997e-6b539c546d91/public_html/wp-content/themes/watch-aembed/inc/core/dbmvs/cache/episodes_1.46298): failed to open stream: No such file or directory in /var/www/17858778-cf11-4d06-997e-6b539c546d91/public_html/wp-content/themes/watch-aembed/inc/core/dbmvs/classes/helpers.php on line 719