Synopsis (From Novelupdates):

Popular for being filled with bugs, the virtual-reality game New Communicate Online (a.k.a. Nekomimi Neko Offline).

A die-hard fan of the game, Sagara Souma, is sent to the game world from the power of a mysterious device.

Though surprised by the sudden turn of events, Souma conveniently knows the laws of the world.

Mastering every bug, using the game’s logic against it, he is soon known as “Maverick Swordsman Souma.”

Raw: https://ncode.syosetu.com/n9078bd/

Glossary:

Prologue
Chapter 1-3: Ventriloquism Potion
Chapter 4-5: The man called Reinhardt
Chapter 6: Nekomimi Neko Offline
Chapter 7-8: Shortcut
Chapter 9-10: Hunt
Chapter 11: Train-chan
Chapter 12-13: Prideful Man
Chapter 14-15: To the depths of the earth
Chapter 16: Above the ones that never give up
Chapter 17: Hanging Spider Thread
Chapter 18-19: What I can do
Chapter 20-21: Classroom Ghost
Chapter 22: Train Mode
Chapter 23: Jump Up
Chapter 24-25: Ghost Dungeon
Chapter 26: Pain of Growth
Chapter 27: Comrade
Chapter 28: Misunderstanding
Chapter 29: The ring story
Chapter 29.5: Side Story – Blessing to the Bride
Chapter 30-31: Trauma
Chapter 32-33: Conscience of Nekomimi Neko
Chapter 34: 1v1
Chapter 35: The battle before the battle
Chapter 36: The morning of the match
Chapter 37: Conclusion

Chapter 38: NPC
Chapter 39-40: Guilds
Chapter 41: Encounter with the unknown
Chapter 42: Wish Fulfillment
Chapter 43: Name
Chapter 44: Bounty Hunting Guild
Chapter 45-46: Golden Stray Slimes
Chapter 47-48: Heart Breaker
Chapter 49: The Last Secret Plan
Chapter 50: Despair
Chapter 51: Mincing Festival
Chapter 52: Escape
Chapter 53: Counter
Chapter 54: Saving Blade
Chapter 55: Triumphant Return
Chapter 56: Gold Coin Gatherer
Chapter 57-58: Hexa-Stab

Chapter 59: Enclosed
Chapter 60-61: To the promised land
Chapter 62: Rare
Chapter 63: Ringo
Chapter 64: Biggest Purchase
Chapter 65: The closest place to paradise
Chapter 66: The Terror of the Nekomimi Neko Mansion
Chapter 67: Fast Solution
Chapter 68: Secret Message
Chapter 69: Thousand Guests
Chapter 70: Before the battle
Chapter 71: Cheat vs Bug
Chapter 72: Merciless conclusion
Chapter 73: The most beautiful thing in this world
Chapter 74: Dojo
Chapter 75: Mirage Skill
Chapter 76: The Meaning of Setsuna
Chapter 77: The remaining 10% is the customary greetings
Chapter 78: Affection Meter Down Trap
Chapter 79: Unwinnable Trial
Chapter 80: Unexpected Danger
Chapter 81: Freezing Time

Chapter 82-83: Fearsome Relationship
Chapter 84: Fear again
Chapter 85: New Power
Chapter 86: Best Excavation Tool
Chapter 87: Cow Tiger Horse Bear
Chapter 88: Yellow Demon
Chapter 89: Welcome to the Slime Mold Forest!
Chapter 90: Slime Mold Fever
Chapter 91: Chain of Death
Chapter 92: Western Trap
Chapter 93: Proper Battle
Chapter 94: Outbreak of War
Chapter 95: A terribly proper battle
Chapter 96: Despairing Sight
Chapter 97: Becoming a Well-Known Adventurer

Chapter 98-99: Fated Reunion
Chapter 100: The one that reigns over fear
Chapter 101: The Game of the Devil
Chapter 102: Beginning Countdown
Chapter 102.5: Side Story – Sacrifice Dungeon
Chapter 102.5 (Part 2): Side Story – Ghost Dungeon
Chapter 103: Their Name
Chapter 104: Barbarism that doesn’t fear gods
Chapter 105: Impatience
Chapter 106: Resurrection of the Evil God
Chapter 107: Freed Demon
Chapter 108: The Last Strike
Chapter 109: The condition of my comrades
Chapter 110: A voice from the yonder
Chapter 111: Eternal Ina
Chapter 112: The last remaining thing
Chapter 113: River Bottom
Chapter 114: Underwater City
Chapter 115: Divine Protection of the Water Dragon
Chapter 116: Berserk Mage
Chapter 117: Level and Strength
Chapter 118: Respective Roads
Chapter 119: Past and Present
Chapter 120: A way too soon future
Chapter 121: The style of Souma
Chapter 122: Supreme Resolve
Chapter 123: Fearsome Growth
Chapter 124: Grow and Adapt
Chapter 125: Silent Passion
Chapter 126: Respective Resolves
Chapter 127: Fatal Mistake
Chapter 128: Calling that name
Chapter 129: Given Title

Chapter 130: The secret of the girl
Chapter 131: Wonder Drug
Chapter 132: The ones who ask
Chapter 133: Sleeping Together
Chapter 134: Bitter Sweet
Chapter 135: Her evolution
Chapter 136: Ring of Unrequited Love
Chapter 137: Chuunibyou Medal
Chapter 138: Yandere Flag in Progress
Chapter 139: The worst choice
Chapter 140: Counter of Death
Chapter 141: Son of a Hero
Chapter 141.5: Side Story – Fake Prince Charming
Chapter 141.5: Side Story 2 – Power of Bonds