Uyu mugani Abanyarwanda bawuca iyo bashaka kumvisha umuntu ko nubwo mugenzi wawe mwaba mutumvikana akagira amakuba udakwiye guhita umusongerana; ko ahubwo ukwiye kumurengera bitewe n’uko ibimubayeho na we byakubaho! Ubwo rero nibwo wumva bagize bati: “Aho umugabo aguye undi aterera yo utwatsi”! Uyu mugani usangiye isoko n’indi migani itatu ari yo: Imana iruta Imanga; Imana iruta ingabo, Imana iruta Imanzi yose yasohotse mu gitabo cy’Ibirari by’Insigamigani. Iyi migani yose imvano yayo ni umwami w’u Rwanda Cyirima Rugwe na Nsoro Bihembe ahakabakaba umwaka wa 1300 (1295 – 1325).
Nkuko byanditswe mu gitabo cy’ Ibirari by’insiganigani, ku mutwe w’umugani ugira uti: “Imana iruta Imanga”; bavuga ko imvano y’iyi migani ari Cyirima Rujugira.
Nyamara hakurikijwe ibyo amateka y’u Rwanda avuga; twamenye ko imvano yayo aho kuba Cyirima Rujugira na Nsoro watwaraga u Bugesera muri icyo gihe, ahubwo ari Cyirima Rugwe na Nsoro Bihembe. Dore uko byagenze:
Igihe kimwe Abanyarwanda bari ku rugerero rw’i Mageragere h’i Kigali cya Mwendo, bukeye Cyirima Rugwe ajya kubasura, ahageze arababaza ati: “Igituma mudashotora u Bugesera ngo mubwendereze twigerageze ni iki”? Babijyamo, bemeranya kubihubukira nta mana yeze (bataraguje); Cyirima ubwe yiyemeza kuba umugaba; bukeye barashibura baratera. Ingabo z’i Bugesera zitwaga Imanga, zibibonye zityo, zemeza Nsoro kuzibera umugaba nka Cyirima, ariko bajya inama yo kudashoka barwana n’Abanyarwanda. Abanyabugesera bakagenda bahunga Abanyarwanda amayembayembo, na bo Abanyarwanda bagakeka ko ari ukubahunga byo kubatinya.
Bageze ku musozi witwa Gihinga, Abanyabugesera baca ibico maze bakubira Abanyarwanda hagati, babatera icyorezo kibi. Ingabo z’u Rwanda zibonye ko zisumbirijwe zisigaye hagati y’urupfu n’umupfumu, zambura Rugwe umuheto we, kugira ngo adakomeza kurwana. Zimaze kuwumwambura, ziminjiramo agafu zata urukubo, zikwirwa imishwaro; Cyirima ariruka, Nsoro amwomaho. Cyirima amaze kubanikira kuko ngo yatebukaga cyane, agera ku mukoke mugari, awusimbutse arateba ntiyawuzimiza, akubita ikirenge ku rutsike rwo hakurya, ikiguja cyawo kirarimbuka kimurundumuriramo! Ubwo Nsoro aba arahashinze amuhagarara hejuru abanguye icumu! Abonye uko Cyirima yihebye amugirira impuhwe, kuko mbere babanaga neza, ati: “Vamo vuba nguhishe Imanga zitaragushokeraho”! Cyirima avamo ariko ubwoba ari bwose, akeka ko amushuka. Nsoro amuhisha mu mwobo arenza ho ibyatsi. Imanga zigeze aho, Nsoro arazirindagiza, ati: “Nimuhogi twigendere Abanyarwanda ni abahanya, Cyirima yansize”! Amaze kwikubura n’Imanga ze, Cyirima asohoka muri wa mwobo, yiruka amasigamana ijoro ryose. Atungutse iwe mu Ruhango rwa Kigali, asanga rubanda bajumariwe bifashe majingwe bagira ngo yapfuye; bamukubise amaso barishima.
Nguko uko umwami w’u Bugesera yanze gusonga umwami mugenzi we w’u Rwanda ahubwo akamuhisha amurengejeho utwatsi bikaba imvano y’umugani ugira uti: Aho umugabo aguye undi atereraho utwatsi.
