Lie-in Heart is a white lion with yellow eyebrows and inner-ears. His nose and eyes are orange. He has a milk-blue mane with ice blue tips. His many tail flames and chest fur match. He wears a yellow vest with burnt-orange sash around the middle, a pair of dark teal pants and wristbands, and dark yellow toed-sandals. He carries a long nihonto-like sword with a maroon sword sheath on the left of his waist.
Lie-in Heart is a very patient soul, to the point of appearing unwilling to act. He waits for the perfect moment to act, but tends to wait days on end for that to happen.
He will make you wait for the perfect moment to do anything, along with a perfect setup. Once the time is ready, Lie-in Heart will make everyone perform whatever they were waiting for to do with a spectacular performance. This is rather risky; it can cause the victim to continue procrastinating to the point where time has run out and the "perfect moment" will never come.
Befriended:"You got me... Looks like it's time for us to be friends."
Being traded:"[player's name] doesn't realize what was lost. I held back before... Never again!"
Receiving food (favorite):"Tastes great!"
Receiving food (normal):"So-so."
Receiving food (disliked):"Is this even ripe?"
Freed from Crank-a-kai: "This is it-my moment to shine. I will follow you wherever you go."
In the anime
Lie-in Heart debuts in EP032. Having skipped out on doing any of his summer homework, Nate visits Bear's house with the intent of collaborating on their homework together. Although Bear has predictably also not started on his work, he is under the influence of Lie-in Heart and refuses to begin, claiming to be waiting for the perfect moment; Lie-in Heart likewise states that Bear is not ready to undergo the task of homework. Nate summons Blazion to get Bear fired up, but Lie-in Heart convinces Blazion that attempting to do all of Bear's homework without preparation will be worse than not doing it at all. Nate and Bear end up spending the day cleaning Bear's room and taking a nap to rest their minds. In the end, Nate wakes up the following day refreshed but his homework still untouched. Lie-in Heart leaves at this point, but Nate has already run out of time to do any homework.
Lie-in Heart is summoned again in EP111, where he tries to stop Oh Bah Gah! from inspiriting Nate.
He was summoned again ten episodes later in EP148 to stop In-Tune from inspiriting everyone in class except for Nate. Then later in EP196, he was summoned along with Ben Tover because they were the only available Yo-kai to be contestants along with Procrastinocchio in Decidevible’s slow-buzz game show.
"Man'ojishi" (which translates as "many-tailed lion") is a homophone to the phrase man wo jishi (Japanese: 満を持し,"at long last").
"Lie-in Heart" is a corruption of the name Lionheart, a popular source of bold-hearted figures, which had first started with King Richard I of England. "Lie in" is also a colloquial term for intentionally oversleeping.
In Spanish, "León Alfa" is literally "Alpha Lion" in Spanish.
In French, "Rugis" is a portmanteau with "Régis" (a French name) and "rugir" (roar).
In Portuguese, "Coração de leão" is tranlated as "Lion Heart".
In Italian, "Leoforte" is derived from "leone" (lion) and "forte" (strong).
Lie-in Heart's "random" nicknames in Yo-kai Watch 2 are: Lionel, Lord Zen, Leon, and Felie-in.