Glass first appeared on the third Wave and was mistaken as the boss of the Wave by the Four Legendary Heroes. She later disregards The Spear Hero, Sword Hero, and Bow Hero as fools, extremely weak, common adventures, and not heroes. She only accepts Naofumi as the only true hero among them due to the events of Naofumi single handily defeating the Soul Eater on his own. She defeated three of the Heroes without breaking any sweat.
Glass forces Naofumi to a duel. She easily overpowers Naofumi, taking his strongest curse series attack without any visible damage. However, Naofumi was able to escape and Glass is forced to leave with the wave coming to an end.
During the Cal Mira Archipelago wave, Glass appears again to reinforce L'Arc and Therese against their fight with Naofumi. Once again, Glass and her allies were forced to retreat due to them running out of time. This time Glass acknowledged Naofumi to be a greater threat, as he grew much stronger in a short amount of time.
After being to forced to flee their second encounter with Naofumi, Glass and her two companions travel to Melromarc in order to train and level-up. While they are there, they encounter Kyo who is holding the Vassal Book against its will. The Vassal Book reveals Kyo's plan to corrupt and control the Guardian Beast called the Spirit Tortoise. However, Kyo then teleports away before they are able to stop them.
Even though they plan to destroy Raphtalia's World by killing all the Legendary Heroes, even Glass, L'Arc and Therese believe Kyo's actions are evil. If his plans succeed, he will have corrupted a sacred Guardian Beast and commit mass murder for his own experiments. As a result, they decide to travel to the Spirit Tortoise to stop Kyo. Despite Kyo's best efforts, they eventually meet Naofumi and have a temporary truce to defeat Kyo. They kill the Spirit Tortoise but Kyo then escapes to their world with the Spirit Tortoise energy. Both they and Naofumi's party decides to travel through to portal to Glass' World.
While they are successfully transported to their world, Kyo had set a trap in the portal so Glass, L'Arc, Therese and Raphtalia are sent to a specialty prison designed for high-level adventurers. However, Raphtalia uses her magic to allow them all to escape. As they run through enemy territory, they are eventually found by Naofumi and Rishia who had rescued Glass' dearest friend - Kizuna.
After reuniting with her long lost comrade and friend, she was scolded by Kizuna for trying to kill Naofumi and the other legendary Heroes. Glass and her fellow heroes ask for forgiveness and the heroes from both worlds decide to work together.
As the Heroes from both worlds work together, they are eventually successful in stopping Kyo for good. which brings temporary peace to their world.
Unfortunately, the peace they had forged in their world would not last for long. Several Vanguards of the Waves had betrayed Glass and Kizuna during their peace talks. Glass' dear friend Kizuna was kidnapped again to an unknown location while the enemy launched an attack on the Heroes' base. Ethnobalt was able to bring Naofumi in a reinforcements and Glass was able to start her search for Kizuna in earnest. They eventually discover that she is being held by the wielder of the Vassal Musical Instrument named Miyaji. After a tough battle, they are able to save Kizuna, but she had been petrified as stone which would take a while to cure.
After Kizuna is cured from her petrification, it becomes painfully clear that she is also under of the effects of a curse series weapon. If she is fully consumed by the weapon, she may die. Desperately, Glass and the other heroes find a partial cure at the Ancient Labyrinth Library. They then use Kizuna's obsession with fishing to fully break her out of the curse.
In order to find a way to combat the enemy's nullification magic, Glass leads Naofumi and the other Heroes to her home nation and dojo. Glass asks her master if she could learn the ancient techniques to repel nullifcation magic. However, her master admits that those techniques had been lost long ago. With Shildina's help they enter the sacred Holy Tool Grotto where they find several weapons which may help against nullification magic.
While in the Holy Tool Grotto, Shildina experiments with her oracle powers to merge with Glass. The test is successful and their merged form is able to replicate the long lost techniques. The Heroes also learn that Glass is a descendant of the long-dead pacifiers similar to Raphtalia. Unfortunately, her bloodline is so diluted that she cannot gain full use of the pacifier powers. However, in their merged form, Shildina is able to assist and they gain the full power and authority of a pacifier.