Isekai Maou to Shoukan Shoujo Dorei Majutsu
The main character was transferred inside of his game with slight differences. When he wakes up he meets 2 girls who are trying to summon, they believe they have got him in a slave contract but their magic was repelled back. Now they are the slaves.
Seijo no Maryoku wa Bannou desu
Manga where the main character the saintess is summoned with someone else and the prince takes the other girl as the saintess. The main character doesn't care and becomes a potion maker.
Shingan no Yuusha
Manga where the main character is transported to another world where he is discarded by the goddess that summons him and he becomes the disciple of the all-seeing goddess.
Long Live Summons Manhua