Roleplay talk:Secret Discord/Part3/@comment-32712012-20180327183812/@comment-32712012-20180328040644

Here's why I think that Tama is the sixth: On the Hyper Division page, the section "The Sensors" shows the following list: Note that the first five each correspond to one of the five senses, so Tama would correspond to a "sixth sense", and would thus be "the sixth".
 * Hikari The Cat (Sight)
 * Kiko The Fox (Hearing)
 * Kota The Rabbit (Touch)
 * Hana The Weasel (Smell)
 * Oishi The Wolf (Taste)
 * Tama The Echidna (???)

As to why they wouldn't have called for help or why she wouldn't have come if they did, it is a good point that they were all very busy, so even if they wanted to call for help or help (depending on who "they" are), they wouldn't have been able to do so.