not that i have ever used a "MAMIRU" verb, but should it have a te-form "MAMIて” instead of MAMIつて
Usually when you coin a new verb in Japanese, it takes the form [X]をする. This is generally shortened to [X]する and conjugates as [X}した and {X]して. The 「する」 part acts similarly as a consonant-stem verb, also known as Godan verbs or -u verbs.
(Technically, 「する」 belongs to the irregular sa category of verbs instead [and it's the only member of its category], but the conjugation is similar in this limited case.)
Colloquially, the above can be shortened further into [X]った and [X]って. While the "S" has been suppressed here, it still plays a part in the conjugation, similar to the role of the suppressed "w" in 買う/買わない/買って.
In rarer cases, [X]る can also be used in place of [x]する (similar to the 買う example in regular Japanese), 'though this would look weird to most people.